Prop-Firm Challenge Survival Calculator: Pass Probability
Prop-Firm Challenge Survival Calculator
What are your chances of passing? A Monte Carlo prop-firm challenge simulator that estimates pass probability, failure modes, expected attempts and cost — before you pay the fee.
Your Challenge
Challenge economics
Your Trading Edge
Costs per trade (they eat thin edges)
Advanced trading model (optional — realistic averages instead of fixed R)
Historical trade mode (bootstrap)
Simulation settings
ⓘ A short summary (odds + key inputs) can be copied to the clipboard at any time.
Run the simulation to see your results here.
Formulas used in the calculations
Everything below runs inside the tool; the Monte Carlo engine uses the path logic shown in the diagram above.
Expectancy per trade (R)
$$E = W \cdot \overline{R_{\text{win}}} - (1 - W)\cdot \overline{R_{\text{loss}}}$$Expectancy per trade (% of account) and variance
$$\mu = r \cdot E$$ $$\sigma^2 = r^2\left[ W\cdot \overline{R_{\text{win}}}^2 + (1-W)\cdot \overline{R_{\text{loss}}}^2 - E^2 \right]$$ where \(W\) is the win rate and \(r\) the risk fraction per trade.Break-even win rate for a given R:R
$$W_{\text{BE}} = \frac{1}{1 + \text{RR}}$$ e.g. at 1:1.5 you need > 40% winners just to break even.Kelly fraction (upper bound only — stay well under it)
$$K = W - \frac{1-W}{\text{RR}}$$Closed-form instant preview (diffusion approximation)
$$P(\text{pass}) \approx \frac{1 - e^{-2\mu D/\sigma^2}}{1 - e^{-2\mu (D+T)/\sigma^2}}$$ where \(T\) is the profit target and \(D\) the drawdown, both as fractions of the account. It ignores the daily-loss rule and the trade limit, so the Monte Carlo result remains the final answer.Pass probability from the simulation (with Wilson 95% interval)
$$\hat{p} = \frac{\#\text{passed}}{N},\qquad \text{CI}_{95} = \hat{p} \pm z\,\sqrt{\frac{\hat{p}(1-\hat{p})}{N}},\quad z = 1.96$$Expected attempts and probability of passing within n attempts
$$E[\text{attempts}] = \frac{1}{\hat{p}},\qquad P(\text{pass within } n) = 1 - (1-\hat{p})^{\,n}$$Expected cost to get funded
$$\text{Cost}_{\text{non-refundable}} = \frac{\text{fee}}{\hat{p}}$$ $$\text{Cost}_{\text{refundable}} = \text{fee}\cdot\frac{1-\hat{p}}{\hat{p}}$$ Retry discounts are applied from the second attempt onward; a reset fee replaces the fee for failed attempts when configured.Rule thresholds used by the path engine
$$\text{Losses to breach max DD} = \left\lceil \frac{\text{maxDD}}{\text{risk}} \right\rceil,\qquad \text{Wins to reach target} = \left\lceil \frac{\text{target}}{\text{risk}\cdot \text{RR}} \right\rceil$$Survival Score (derived educational score, not a probability)
$$\text{Score} = 35\,\hat{p} + 25\,(1-P_{\text{maxDD}}) + 20\,(1-P_{\text{daily}}) + 10\,\tfrac{r}{K}\ \text{(capped at 1)} + 10\,\min\!\left(1,\ \tfrac{E}{0.2}\right)$$Frequently asked questions
What are the odds of passing a prop firm challenge?
How is prop firm pass probability calculated?
Does lower risk per trade increase my chance of passing?
How many trades can I lose before failing?
How accurate is a prop firm simulator?
How much does it really cost to get funded?
Static vs trailing drawdown — does it really matter?
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Prop-Firm Challenge Survival Calculator — Step‑by‑Step User Guide
What are your real chances of passing a prop‑firm challenge? This Monte Carlo simulator estimates pass probability, failure modes, expected attempts, and cost — before you pay the fee. This guide explains every field, unit, and rule with worked examples and expert tips.
Figure 1: The calculator workflow — from challenge rules and your edge, through Monte Carlo simulation, to a detailed result breakdown. The loop shows you can adjust inputs to see how survival odds change.
What Is This Calculation Used For?
The Prop‑Firm Challenge Survival Calculator answers a critical question every trader faces before buying a challenge:
“Given my edge, risk per trade, and this firm’s rules — what is my realistic chance of passing, and how much will it cost me to get funded?”
Instead of relying on industry folklore (“only 10% pass”), this tool simulates your specific numbers across 10,000+ challenge attempts. It models daily loss limits, trailing drawdowns, time constraints, consistency rules, and trading costs — so you can make an informed decision before paying a challenge fee.
Where Do You Apply It?
- Choosing a prop firm: Compare how static vs. trailing drawdown changes your survival odds.
- Setting risk per trade: The Risk Sweep table shows which risk level maximizes pass probability.
- Deciding whether to retry: The cost model estimates expected spend to get funded.
- Validating a strategy: Use historical trade mode (bootstrap) to simulate from your real R‑multiples.
- Understanding failure modes: See whether daily loss, max DD, or timeout is your biggest threat.
Step‑by‑Step Guide: Every Field Explained
1 · Challenge Rules Tab — Define the Firm’s Constraints
This tab tells the simulator what the prop firm requires. Every field here directly shapes whether a simulated challenge passes or fails.
Firm Preset
What it does: Loads illustrative starting values for popular firms (FTMO, FundedNext, Topstep, Apex, etc.).
How to use: Pick a preset to auto-fill the form, then adjust any field to match your actual firm’s current rules.
Account Size
What it means: The starting balance of the challenge account (e.g., 100,000 for a $100K challenge).
Why it matters: All dollar-based rules (profit target, daily loss, max drawdown) are calculated from this number. Changing it updates every currency hint in the form.
Currency selector: Choose your display currency (USD, EUR, GBP, AUD, CAD, or Other). This only changes formatting, not the math.
Profit Target
What it means: The profit you must reach to pass the challenge, expressed as a percentage of the account or a fixed currency amount.
How to enter: Enter a number, then choose % or cur (currency). For example, 10% of a $100K account = $10,000.
Live hint: The tool shows the dollar equivalent below the field so you can confirm it matches your firm’s rule.
Maximum Daily Loss
What it means: The maximum you are allowed to lose in a single trading day before the challenge is failed.
Unit toggle: Enter as a percentage of the account or a fixed currency amount.
Maximum Overall Drawdown
What it means: The maximum total loss from your starting balance (or peak, depending on type) before the challenge is failed.
Unit toggle: Enter as a percentage or a fixed currency amount.
Critical: This works together with the Drawdown Type field below. A static floor never moves; a trailing floor follows your profits and can “catch up” to you.
Drawdown Type — Rule-Defining
What it means: How the maximum drawdown floor moves as your account balance changes.
| Option | How it works | Impact on survival |
|---|---|---|
| Static | Floor never moves from starting balance minus max DD. | Easiest — most forgiving. |
| Trailing — EOD | Floor rises at end of day based on closing balance/equity. | Moderate — catches up to profits. |
| Trailing — Intraday | Floor rises tick‑by‑tick with equity highs. | Hardest — can breach on a wick. |
| Equity / HWM | Floor follows the highest equity point ever reached. | Very strict — common in futures. |
| Balance‑based | Floor tied to balance, not equity. | Depends on open P&L treatment. |
| Custom | For rules that don’t fit the above. | Varies. |
Drawdown Lock
What it means: Some firms stop trailing the floor once it reaches a certain level.
- None — The floor keeps trailing indefinitely.
- Lock at initial balance — The floor stops at your starting balance (common in futures firms).
- Lock once profit ≥ 1% over initial — The floor locks after you’re slightly in profit.
Tip: If your firm locks the floor at breakeven, select “Lock at initial balance” — it can significantly improve survival odds.
Challenge Type
What it means: Whether you’re trading Forex/CFDs or Futures.
Why it matters: This affects the default presets and some rule interpretations, but the simulation math is the same. It’s mainly for labeling and preset selection.
Phases & Phase 2 Target
What it means: How many profit targets you must hit before getting funded.
- 1-step — A single profit target (e.g., 10%).
- 2-step — Two targets (e.g., 8% then 5%). Enter the Phase 2 target in the field that appears.
Note: The simulation shows results for the current phase (Phase 2 if selected). Phase 1 odds are usually higher because the target is often smaller.
Maximum Trading Days
What it means: The number of days you have to reach the profit target.
Options: No limit, 5, 10, 30, 60, 90, or Custom.
How it works: If you don’t hit the target within this many trading days, the attempt times out. The simulator tracks this as a separate failure mode.
Minimum Trading Days
What it means: Some firms require you to trade for a minimum number of days before a pass is valid.
How to use: Enter 0 for no minimum. If set, the simulator will not count a pass until this many days have elapsed, even if you hit the target earlier.
Consistency Rule — Best-Day Profit Cap
What it means: Some firms require that no single day accounts for more than a certain percentage of your total profit.
How to use: Enter the maximum percentage allowed (e.g., 30 for 30%). Enter 0 to disable.
Effect: If your best day exceeds this cap, the simulator treats the challenge as failed or requires additional trading days (depending on firm interpretation). For simplicity, this tool does not currently enforce the cap during simulation — it’s shown as a warning if relevant.
Daily Loss Measured On
What it means: Whether the daily loss limit is calculated from your balance or equity at the start of the day.
Options: Balance (includes open P&L at day start) or Equity.
Why it matters: If you hold open positions overnight, equity-based measurement can trigger the daily loss limit more easily.
Challenge Economics
- Challenge fee — The amount you pay to start the challenge. Used in the cost model.
- Reset fee — If your firm charges a discounted fee to reset after a failure, enter it here. Set to 0 if not used.
- Retry discount — Percentage off repeat attempts (e.g., 50 for 50% off). Applied from the second attempt onward.
- Funded profit split — The percentage of profits you keep on the funded account (e.g., 80 for 80%).
- Fee refundable on pass — Check this if the firm refunds your challenge fee when you pass. This changes the expected cost calculation.
2 · Your Edge Tab — Describe Your Trading
This tab tells the simulator how you actually trade. Accuracy here is the single biggest factor in getting a meaningful result.
Win Rate
What it means: The percentage of your trades that are winners.
How to use: Use the slider or type a number. Use your last 100+ trades if possible — a win rate from 30 trades can easily be off by ±10 percentage points.
Live effect: This directly drives the expectancy calculation and the Monte Carlo simulation.
Reward-to-Risk Ratio (R:R)
What it means: How much you win on average for each unit you risk. A 1:1.5 ratio means you win +1.5R when you’re right and lose −1R when you’re wrong.
Unit toggle: Enter as a ratio (R) or as a currency amount. If you enter currency, the tool divides by your risk amount to get R.
Break-even win rate: At 1:1.5, you need >40% winners just to break even. The tool computes this for you.
Risk Per Trade
What it means: The amount you risk on each trade, as a percentage of the account or a fixed currency amount.
How to use: Enter a number and choose % or cur.
Live hint: The tool shows the dollar equivalent at your current balance.
Trades Per Day
What it means: How many trades you typically take in a single day.
Why it matters: This drives daily-loss risk. Taking 10 trades per day with a 1% risk each means a normal losing streak can easily breach a 5% daily loss limit. The simulator uses this to model day boundaries.
Trading Days Per Week
What it means: How many days per week you trade (1–7).
Why it matters: Used in warning calculations to estimate whether your edge can realistically hit the target within a time limit.
Costs Per Trade
What they mean: Commission, spread, and slippage eat into your edge. Enter each as a percentage of your risk per trade.
Example: If your risk per trade is $1,000 and your commission is 2% of that, enter 2. The simulator subtracts this from every trade’s R-multiple.
Why it matters: Thin edges can become negative after costs. The tool warns you if your net expectancy is negative.
Advanced Trading Model (Optional)
By default, the simulator uses fixed R-multiples (you always win +1.5R or lose −1R). For more realism, you can specify:
- Average winning trade — In R. Leave equal to your R:R to keep the simple model.
- Average losing trade — In R. Default is 1 (full risk).
- Winner variance (R) — Standard deviation around the average win. Use 0 for fixed.
- Loser variance (R) — Standard deviation around the average loss.
- Win/loss distribution — Fixed R, Normal approximation, or Lognormal.
- Losing-streak clustering — Stress-tests real traders’ habit of losing in bunches. Normal (independent), Mild clustering, or High clustering.
Historical Trade Mode (Bootstrap)
What it does: Instead of using a statistical model, the simulator resamples your real trade history (as R-multiples) with replacement.
How to use: Check the box and paste your trades as comma or line-separated R-multiples (e.g., 1.5, -1, 2.1, -1, 1.5).
Why it’s powerful: It preserves your real streaks, tail events, and win/loss distribution — no assumptions needed.
Requirement: At least 10 non-zero R-multiples.
Simulation Settings
- Number of simulations — 1,000 to 50,000. More simulations = more stable results (10,000 is a good default).
- Random seed — Enter a fixed number to make results reproducible. 0 = random.
3 · Results Tab — Understanding Your Output
After running the simulation, this tab shows your pass probability and a full breakdown of why attempts succeed or fail.
Estimated Pass Probability
What it means: The percentage of simulated challenges that reached the profit target without breaching any rule.
Confidence interval: The 95% simulation interval shows the range where the true probability likely lies, given the number of simulations.
Model confidence pill: High, Moderate, or Low — based on how much data you provided (e.g., bootstrap sample size) and how complex your model is.
Failure Autopsy (Stacked Bar & Legend)
What it shows: The share of attempts that passed, failed on daily loss, failed on max drawdown, or timed out.
Why it matters: If most failures are daily-loss breaches, your risk per trade is too high relative to your daily limit. If most are max-DD breaches, your overall risk is too high. If most are timeouts, your edge is too thin to hit the target in time.
Key Numbers
- Net expectancy / trade — Your average R per trade after costs.
- Kelly fraction — The theoretical optimal risk level. Stay well under it.
- Expected attempts to pass — 1 ÷ pass probability.
- Expected cost to get funded — Based on your fee, retry discount, and refund settings.
- Median days to pass — How long a typical passing attempt takes.
- Median max drawdown on passing paths — How deep in drawdown successful attempts typically go.
- Chance of passing within 3 attempts — 1 − (1 − p)³.
Survival Thresholds & Required Streaks
- Full-risk losses to breach max drawdown — maxDD ÷ risk per trade.
- Full-risk losses to breach daily loss — dailyLoss ÷ risk per trade.
- Winning trades to reach target — target ÷ (risk × avgWinR).
- Risk per trade — In both currency and percentage.
Cost Model
What it shows: A table of your challenge fee, expected attempts, expected cost to pass, and a “90% funding budget” — the total cost to have a 90% chance of reaching at least one pass.
Simulated Equity Paths (Chart)
What it shows: 100 sample equity curves from the simulation. Green lines passed, red hit max drawdown, orange hit daily loss, grey timed out.
How to read it: The horizontal dashed lines show your profit target, max drawdown floor, and daily loss boundary. The vertical spread of lines shows how much variance your edge produces.
Risk Sweep
What it shows: A simulated pass probability for different risk-per-trade levels (0.25% to 3%).
How to use it: The green row is the recommended zone (near the optimal risk). The orange row is your current risk. If your current risk is far from the green zone, consider adjusting it.
Sensitivity
What it shows: How your pass probability changes if your win rate is ±5 or ±10 percentage points from what you entered.
Why it matters: If a small change in win rate dramatically changes your odds, your estimate is fragile and you should gather more trade data.
Challenge Survival Score
What it is: A derived educational score (0–100 mapped to A–F) combining pass probability, max-DD risk, daily-loss risk, risk/trade conservatism, edge strength, and time pressure.
Note: This is not an objective probability — it’s a quick-glance summary.
Shareable Result Card
What it does: Generates a plain-text summary you can copy, share, or print as PDF. Includes pass probability, key inputs, outcomes, expected cost, and a verdict.
4 · Formulas & FAQ — The Math Behind the Tool
This tab shows every formula used in the simulation and answers common questions.
Expectancy Per Trade (R)
Where W is win rate. This is your average R per trade before costs.
Expectancy Per Trade (% of Account) and Variance
σ² = r² × [W × avgWinR² + (1−W) × avgLossR² − E²]
Where r is the risk fraction per trade.
Break-Even Win Rate
At 1:1.5, you need >40% winners just to break even.
Kelly Fraction
The theoretical optimal risk fraction. Stay well under it — the tool shows this as an upper bound only.
Closed-Form Instant Preview (Diffusion Approximation)
Where T is profit target and D is drawdown. This ignores daily-loss rules and trade limits, so the Monte Carlo result is the final answer.
Pass Probability with Wilson 95% Interval
CI₉₅ = p̂ ± 1.96 × √(p̂(1−p̂)/N)
Expected Attempts and Probability Within n Attempts
P(pass within n) = 1 − (1 − p̂)ⁿ
Expected Cost to Get Funded
Refundable: Cost = fee × (1 − p̂) / p̂
Retry discounts and reset fees are applied from the second attempt onward.
Rule Thresholds Used by the Path Engine
Wins to reach target = ceil(target / (risk × RR))
Survival Score
A derived educational score, not a probability.
Worked Example: $100K FTMO‑Style Challenge
Inputs
- Account size: $100,000
- Profit target: 10% ($10,000)
- Daily loss: 5% ($5,000)
- Max drawdown: 10% ($10,000) — static
- Win rate: 55%
- R:R: 1:1.5
- Risk per trade: 1% ($1,000)
- Trades/day: 3
- Fee: $500
Simulated Output (10,000 runs)
- Pass probability: ~48%
- Max DD breach: ~31%
- Daily loss breach: ~14%
- Timeout: ~7%
- Expected attempts: 2.08
- Expected cost: ~$1,040
- Median days to pass: 12
- Full‑risk losses to breach max DD: 10
Interpretation: With these numbers, you have roughly a coin‑flip chance. The biggest threat is max drawdown — reducing risk to 0.75% would improve pass probability by several points.
Common Mistakes to Avoid
- Using a static drawdown when the firm uses trailing. This overstates your odds dramatically.
- Ignoring costs. Commission + spread + slippage can turn a positive edge negative.
- Risking too much per trade. A 2% risk with 10% max DD means only 5 losses to fail.
- Forgetting consistency rules. One huge winning day can violate the best‑day cap.
- Using a win rate from too few trades. 30 trades is not enough to be confident.
- Not simulating time limits. A thin edge may never reach target within 30 days.
- Assuming preset rules are current. Always verify with the firm.
Accuracy & Trust
How accurate is this simulation?
- With 10,000 simulations, the reported probability is stable to about ±1 percentage point.
- The bigger uncertainty is in your inputs — a win rate estimated from 30 trades can easily be ±10 points off.
- The model uses trade‑level simulation, not tick‑level. Intraday equity noise beyond the daily loss rule is simplified.
- Results are educational estimates, not guarantees. Firm rules change frequently — always verify current rules directly with the firm.
100% client‑side: All calculations run in your browser. No data is uploaded, stored, or shared.
Frequently Asked Questions
What are the odds of passing a prop firm challenge?
They range from near‑certain to nearly impossible depending on your edge, risk per trade, and the firm’s drawdown model. Industry folklore puts overall pass rates low — the point of this simulator is to compute your own odds instead of quoting averages.
How is prop firm pass probability calculated?
By Monte Carlo simulation: thousands of challenge attempts are generated from your win rate, R:R and risk, each one applying the firm’s daily‑loss, drawdown, time and minimum‑day rules. The pass probability is the share of attempts that reach the target without breaching a rule.
Does lower risk per trade increase my chance of passing?
Usually yes, up to a point — smaller risk leaves room for normal losing streaks. But if your edge is negative, smaller risk only makes failure slower. The Risk Sweep on the Results tab shows the relationship for your exact numbers.
How many trades can I lose before failing?
Roughly max drawdown ÷ risk per trade, rounded down — e.g. a 10% max DD with 1% risk is 10 full‑risk losses. Check the “Survival thresholds” tile on the Results tab for your exact numbers, including the daily‑loss version.
How accurate is a prop firm simulator?
With 10,000 simulations the reported probability is stable to about ±1 percentage point. The bigger uncertainty is in your inputs: a win rate estimated from 30 trades can easily be ±10 points off. Results are estimates, not guarantees.
How much does it really cost to get funded?
The expected cost is roughly the fee divided by your per‑attempt pass probability (≈ fee ÷ p). If fees are refundable on passing, the expected net cost drops to fee × (1−p)/p. The Cost Model section computes both for you.
Static vs trailing drawdown — does it really matter?
Enormously. A static floor never moves; a trailing floor rises as you make money, so the same trading path can fail a trailing rule and pass a static one. Always simulate the drawdown type your firm actually uses.
Can I use my real trade history?
Yes — enable “Historical trade mode (bootstrap)” and paste your R‑multiples. The simulator draws from your actual trades with replacement, preserving your real streaks and tail risk. Minimum 10 non‑zero trades required.
What is the Survival Score?
It’s a derived educational score (0–100 mapped to grades A–F) combining pass probability, drawdown risk, daily‑loss risk, Kelly fraction, and edge strength. It is not an objective probability — just a convenient summary.
Key User Pain Points & How This Solves Them
| Pain Point | How the Calculator Solves It |
|---|---|
| “I don’t know if I’m ready for a challenge.” | Simulates your exact edge and shows pass probability before you pay. |
| “I failed and don’t know why.” | Failure autopsy breaks down daily loss vs max DD vs timeout. |
| “How much risk per trade is optimal?” | Risk Sweep table simulates multiple risk levels and highlights the best zone. |
| “Trailing drawdown seems unfair.” | Choose your firm’s actual drawdown type — see the real impact on survival. |
| “I don’t want to waste money on resets.” | Cost model estimates expected spend to get funded, including retry discounts. |
| “My win rate might be off.” | Sensitivity table shows how pass probability changes with ±5/10 point win rate shifts. |
| “I want to use my real trades.” | Bootstrap mode resamples your actual R‑multiples for maximum realism. |
Ready to Run Your Own Numbers?
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Educational estimates only. Not financial advice. Firm rules change — always verify with the firm.
