How to Calculate Maximum Drawdown & Relative Loss (Crucial for Prop Firm Challenges)
One bad week can end a funded account that took months to earn. The drawdown math is simple; what differs is how each prop firm measures it. Here's every rule decoded.
By Mairy Nuñez, Founder & CEO
Every prop firm challenge has two numbers that end careers: the daily loss limit and the maximum drawdown. Traders fail challenges they were winning, not because the strategy broke, but because they never mapped where the kill line actually sits. The math takes thirty seconds; the confusion is in which version of 'drawdown' your firm uses.
The drawdown formula
Drawdown % = (peak equity − trough equity) ÷ peak equity · Recovery needed = 1 ÷ (1 − drawdown) − 1Peak $10,000, drop to $8,000, that's a 20% drawdown, and recovering needs +25%, not 20%. Gains and losses aren't symmetrical, which is the entire argument for keeping drawdowns shallow:
−10%
- Gain needed to recover
- +11.1%
−20%
- Gain needed to recover
- +25%
−30%
- Gain needed to recover
- +42.9%
−40%
- Gain needed to recover
- +66.7%
−50%
- Gain needed to recover
- +100%
The [drawdown recovery calculator](/tools/drawdown-recovery-calculator) computes this for any loss. Past −30%, the math starts fighting you hard.
Static vs trailing drawdown: the rule that decides everything
Prop firms measure the same pain three different ways. Knowing which one applies to your account changes how you manage winners:
Static (fixed)
- How it works
- Floor stays at a fixed level below the starting balance
- Example on $100k, 10% max
- Equity can't touch $90,000, ever
Trailing
- How it works
- Floor follows your equity high-water mark, locks in some firms once it reaches the initial balance
- Example on $100k, 10% max
- Peak $104k → floor $94k; peak $108k → floor $98k
End-of-day trailing
- How it works
- Floor only moves up on the closed daily balance, intraday peaks don't count
- Example on $100k, 10% max
- Spiked to $110k, closed $103k → floor moves to $93k
Read your firm's rule carefully: the same −$8,000 day passes a static account and fails a trailing one that ratcheted up on last week's profits.
The traps that fail funded traders
- Open P&L vs closed balance. Some firms trail on unrealized highs: a $5,000 open profit you didn't close can raise your floor and later cost the account.
- The daily limit is per day, not per trade. A −3% morning means the afternoon must defend −2% remaining room; many traders revenge-trade into the wall.
- Trailing floors move up, never down. Banking a big win early in the challenge ratchets your floor up before you have buffer. Some traders deliberately keep early equity gains small to keep the floor low.
- Reset math. A $50k challenge at $500 needs ~5+ evaluations on average for a 20% passer; run the real expected cost with the prop firm ROI calculator before paying.
How to survive the rules
- Risk 0.5% per trade, not 1–2%. With a 10% max drawdown, ten straight 1% losses put you at the floor with zero room for variance.
- Set a personal daily stop tighter than the firm's. If the rule is −5% daily, stop yourself at −2%; the challenge is won by not failing, not by trading every day.
- Know the floor today, not at signup. Trailing floors move, so the distance to failure changes daily. Recalculate before every session.
- Build a buffer before sizing up. The first 3–5% of profits are armor for the rest of the challenge, not the time to get aggressive.
Drawdown vocabulary cheat sheet
Maximum drawdown
- Meaning
- Worst peak-to-trough equity decline on record
High-water mark
- Meaning
- The highest equity the account has ever reached
Trailing drawdown
- Meaning
- A loss floor that follows the high-water mark upward
Daily loss limit
- Meaning
- Max allowed loss inside a single trading day
Recovery factor
- Meaning
- Net profit ÷ max drawdown, how efficiently equity recovered
Drawdown, explained like you're five
Forget the percentages for a minute, the whole rule is a helium balloon on a string.
The balloon and the ceiling
Imagine your trading account is a helium balloon on a string you're holding. The balloon flying high is you winning. The game has one rule: the balloon can never sink below your hand. Two kinds of games exist, and they sound similar but aren't:
- Static drawdown: your hand stays at the same height forever. The balloon can fly anywhere above it, huge freedom.
- Trailing drawdown: your hand follows the balloon up and never comes back down. Every new high you reach pulls the floor up behind you.
- Daily loss limit: inside one afternoon, the balloon can't sink more than one short string, no matter how high it flew.
Why this is dangerous
Now imagine your balloon had its best day ever, and you celebrated without noticing your hand climbed with it. Two ways that goes wrong:
- The mistake many make: 'I was up $5,000, so I can afford a red day.' Under a trailing rule, yesterday's win already raised the floor, so today's 'affordable' loss touches it and pops the balloon.
- The reality: the further the balloon flies, the closer the floor creeps behind it. Big early wins feel like safety; under trailing rules they quietly shorten your string.
In short: a funded account is a balloon with a floor that may follow it. Check every morning where the floor is, and never let the balloon sink to your hand.
Drawdown tolerance is also what makes compounding honest, the power of compounding in trading shows why deep drawdowns break the growth curve.
Frequently asked questions
Does a trailing drawdown move on open (unrealized) profits?
Depends on the firm. Some trail on the highest equity reached, including open P&L; others only on end-of-day closed balances. Read the exact rule before your first trade, it changes how you should take profits.
What happens when you breach the max drawdown?
The account is closed immediately, usually positions are force-liquidated and the challenge or funding is lost. There's no warning and no appeal, which is why the floor matters more than any setup.
Is a 10% drawdown limit realistic for normal trading?
Yes, but it demands small risk: 0.5% per trade gives you 20 consecutive losses of room, 1% gives you 10, and losing streaks of 10+ happen to good systems. Many pros run 0.25–0.75% specifically for challenge rules.
How do I recover from a big drawdown without revenge trading?
Shrink risk to half your normal size and rebuild with the system's normal trades, not bigger ones. Recovery is a compounding problem: at −30% you need +43%, and doubling your risk is how −30% becomes −60%.
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