TL;DR
A prop firm evaluation calculator converts your account size, profit target, and maximum drawdown into a maximum safe position size before you risk a paid attempt; on a $100,000 FTMO-style account with a 10% profit target and 10% max drawdown, that math typically caps risk per trade at 0.5% to 1% of the account to survive the swings needed to reach the target.
Key Takeaways
- 1.FTMO's 2026 structure requires a 10% profit target in Phase 1 and 5% in Phase 2, both capped by a 10% max drawdown and a 5% max daily loss.
- 2.Topstep uses a trailing 6% max drawdown and a 30% consistency rule, meaning no single day can account for more than half of total profit.
- 3.Apex Trader Funding switched from monthly subscriptions to one-time evaluation fees in March 2026 and uses real-time trailing drawdown based on peak intraday balance.
- 4.A calculator needs four inputs to be useful: account size, profit target percentage, max drawdown percentage, and your historical win rate or average R-multiple.
- 5.Most blown evaluations come from position sizing that would have worked on a personal account but breaches a firm's daily loss limit on a single bad day.
A prop firm evaluation calculator answers one question: given this account size, this profit target, and this drawdown limit, how much can I risk per trade without a normal losing streak ending the challenge? The short answer for a typical $100,000 account with a 10% target and 10% max drawdown is 0.5% to 1% risk per trade, which leaves enough room to survive a run of five or six losses in a row.
The reason this math matters more for a funded challenge than for a personal account is that the drawdown limit is fixed and enforced automatically. A personal account lets you decide to take a break after a bad week; a prop firm account gets disabled the moment the drawdown line is crossed, regardless of intent.
How does a prop firm evaluation calculator work?
The calculator takes your account size and multiplies it by the max drawdown percentage to get your total dollar cushion, then divides that cushion by the number of losing trades you want to survive in a row to get your max risk per trade. On a $100,000 account with a 10% drawdown ($10,000 cushion) sized to survive 10 straight losses, that's $1,000, or 1%, per trade before other costs like spread and commission.
Why 10 losses, not 5
Sizing for only 5 consecutive losses looks fine on paper but fails in practice, since most trading strategies with a 40-50% win rate will produce a streak of 8 to 10 losses within a few hundred trades purely from variance.
This calculation is the same core formula every prop firm calculator template uses, whether it's a spreadsheet or a dedicated app: cushion divided by planned loss streak equals safe risk per trade, and that number should already account for the firm's daily loss limit, not just the overall drawdown.
What numbers do you need before you calculate your challenge?
Four inputs make the calculator accurate instead of theoretical: account size, the profit target percentage for your current phase, the maximum drawdown percentage (and whether it's static or trailing), and your own historical win rate or average R-multiple from at least 30 prior trades. Skipping the fourth input is the most common mistake, since it forces you to guess at a win rate instead of using your real one.
| Input | Where to find it | Why it matters |
|---|---|---|
| Account size | Firm's evaluation product page | Sets the dollar value of every percentage limit |
| Profit target % | Firm's phase rules | Determines how many R multiples you need to bank |
| Max drawdown type | Firm's rules (static vs trailing) | Trailing drawdown shrinks your cushion as you profit |
| Historical win rate | Your own trade journal, 30+ trades | Replaces guesswork with your actual edge |
A trader who plugs in a guessed 60% win rate when their real number is 45% will size positions too aggressively and fail the challenge on variance alone, which is why a journal like TraderSync or Tradervue that reports your real win rate matters as much as the calculator itself.
How much profit do you need to pass FTMO, Topstep, and Apex in 2026?
The three most-searched prop firms run meaningfully different rules in 2026, and a calculator built for one will size you wrong on another. FTMO uses a two-phase structure with fixed, static drawdown limits, Topstep uses a single combine with a trailing drawdown and a consistency rule, and Apex uses real-time trailing drawdown based on intraday peak balance rather than end-of-day balance.
| Firm | Profit target | Max drawdown | Notable rule |
|---|---|---|---|
| FTMO | 10% (Phase 1), 5% (Phase 2) | 10% static, 5% daily | Profit split starts at 80%, scales to 90% |
| Topstep | Set by account size | 6% trailing | 30% consistency rule: no day over 50% of total profit |
| Apex Trader Funding | Set by account size | Trailing, based on intraday peak | One-time evaluation fee since March 2026, no time limit |
Topstep's consistency rule is the one traders most often overlook in their calculator inputs: even if you hit the overall profit target, a single day that produced more than half your total profit can fail the evaluation, which means your calculator needs a per-day profit cap, not just a per-trade risk cap.
How do you calculate safe position size for a funded challenge?
Position sizing walkthrough for a $100,000 evaluation
- 1
Find your dollar cushion
Multiply account size by max drawdown percentage. On $100,000 at 10% static drawdown, that's a $10,000 cushion before the account fails.
- 2
Pick a loss-streak buffer
Divide the cushion by 10 (a realistic worst-case losing streak for a 40-50% win rate strategy) to get maximum dollar risk per trade: $1,000, or 1% of the account.
- 3
Check the daily loss limit separately
FTMO caps daily loss at 5% ($5,000 on a $100,000 account). Make sure your planned number of trades per day, multiplied by max risk per trade, stays under that figure.
- 4
Convert dollar risk to position size
Divide your dollar risk per trade by the stop-loss distance in dollars per share or per contract to get the number of shares or contracts to trade.
- 5
Back-test against your real win rate
Run the sizing against your last 30-50 trades to confirm the profit target is reachable within a realistic number of trading days at this risk level.
Step 3 catches the mistake that fails more challenges than any other: a risk-per-trade number that respects the overall drawdown but ignores the daily loss limit, which is usually a smaller, faster trigger than the overall drawdown on firms like FTMO.
What mistakes blow up prop firm evaluations?
The most expensive mistake
Increasing position size after a winning streak to 'catch up' on the profit target faster is the single most common cause of failed evaluations, since it concentrates risk right when a reversion to your real win rate is statistically due.
Pros
- A calculator forces you to size for your worst realistic losing streak, not your best week
- Static drawdown firms (FTMO) are more forgiving of a slow start than trailing drawdown firms
- One-time fee models (Apex, since March 2026) remove the pressure of a monthly subscription clock
- Real win-rate data from a trading journal replaces guesswork in every calculation above
Cons
- Trailing drawdown firms punish early profits by shrinking your cushion as the account grows
- Consistency rules (Topstep) require tracking a daily profit cap most personal accounts never need
- A calculator can't account for slippage or spread widening during high-volatility news events
- Recalculating position size after every account milestone is easy to forget and easy to skip
Every one of these mistakes is a sizing problem, not a strategy problem: traders who fail evaluations usually have a strategy that would have been profitable at half the position size they actually used.
The second most common mistake is trading a second attempt with the same sizing that failed the first one. If an evaluation fails on drawdown, the correct adjustment is to cut position size by 30-50% on the retry, not to run the identical numbers again and hope for a different variance outcome.
Which tools track this automatically once you're funded?
Once you pass an evaluation and move to a funded account, a trading journal that tracks drawdown in real time removes the need to recalculate by hand after every trade. Tools built for this include a dedicated Evaluator or challenge-tracking feature that checks your live trade history against the specific firm's rules rather than a generic template.
- Confirm whether your firm uses static or trailing drawdown before choosing a tracking tool
- Set a daily loss alert at 80% of the firm's daily limit, not at the limit itself
- Recalculate safe position size after every 10% account growth on trailing drawdown accounts
- Log every trade's R-multiple so your win rate assumption stays current, not guessed
- Review the firm's consistency rule (if any) weekly, not just at evaluation deadline
A journal that flags a rule violation the same day it happens is worth more during a funded challenge than one that only summarizes performance at month end, since prop firm rule breaches are enforced instantly, not on a monthly review cycle.
Automating the alert side is worth the setup time too. A simple Make.com scenario that pulls your daily P&L from a broker webhook and pings you at 80% of the daily loss limit costs nothing beyond the time to build it, and it catches the exact failure mode, trading past a limit while distracted, that a weekly manual check will miss.
The verdict: build your own calculator or use a template?
The math behind a prop firm evaluation calculator is simple enough to build in a spreadsheet in about 20 minutes: account size, drawdown percentage, planned loss streak, and daily loss limit are the only four numbers involved, and the formulas don't change firm to firm, only the inputs do. What changes the outcome isn't the calculator, it's plugging in your real historical win rate instead of an optimistic guess, and rechecking the daily loss limit separately from the overall drawdown.
Build a version of this yourself with the four inputs above, run it against your last 30 trades before paying for any evaluation, and you'll size correctly on the first attempt more often than traders who skip straight to trading the challenge live.
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