What the prop firm calculator helps you plan
Funded-account challenges pay out only if you reach a profit target without breaking two hard rules: a daily loss limit and a maximum overall loss. Many failed challenges break a rule long before time runs out. The calculator turns those rules into numbers you can trade with: how many losing trades in a row each limit allows at your risk per trade, a size hint for a typical stop, and how far you are from the target.
How to use it
- Enter the account size and the challenge rules — daily loss limit, maximum loss and profit target — in percent.
- Enter your risk per trade as a percentage of the account.
- Add your current profit (negative if you are down) to track progress.
- Enter a typical stop in pips and your average reward-to-risk to get a lot-size hint and an estimate of the winning trades still needed.
The calculation uses static rules: limits measured from the initial account size and a fixed dollar risk per trade. Check your firm's rules — some use a trailing drawdown, equity-based daily limits or a reset at a specific server time.
The formulas
risk per trade ($) = account × risk %
daily limit ($) = account × daily loss %
room to max loss ($) = account × max loss % + current profit
losses to daily limit = ceil(daily limit ÷ risk per trade)
losses to max loss = ceil(room to max loss ÷ risk per trade)
lot hint = risk per trade ÷ (stop in pips × $10)
wins needed ≈ remaining target ÷ (risk per trade × R:R)
The daily figure is capped by the room left to the maximum loss, and the lot hint assumes a pair quoted in US dollars.
Worked example
A $100,000 challenge with a 5% daily limit, a 10% maximum loss and a 10% target, risking 1% per trade:
- Risk per trade: $1,000
- Daily limit: $5,000 — the 5th loss in one day hits it, so 4 losses are survivable
- Maximum loss: $10,000 — 10 losses in a row from the start
- With a 20-pip stop on EUR/USD: $1,000 ÷ (20 × $10) = 5.00 lots
- Target: $10,000 — about 5 net winners at 2R
Raise the risk to 2% and the picture changes fast: at $2,000 per trade the 3rd loss in a day breaches the 5% limit, leaving room for only two losing trades. That single change explains many failed challenges.
Common mistakes
- Watching closed trades only. Many firms measure the daily loss on equity, including open positions. A trade that is down 4% intraday can breach a 5% rule before you close anything.
- Correlated positions. Trades on EUR/USD, GBP/USD and EUR/GBP can lose together. Count them as one larger risk.
- Racing the target. Raising size near the end of a challenge is a quick way to hit the daily limit.
- Ignoring commission and swap. They count toward the loss limits at most firms.
- Not knowing the reset time. The trading day often resets at a fixed server time, not at midnight where you live.
For instruments other than USD-quoted pairs, get an exact size from the position size calculator.