How a trailing drawdown works
Trailing drawdown floor = Highest balance − Max drawdown
Take a $50,000 account with a $2,000 limit. The floor starts at $48,000. When the account first reaches $51,800, an intraday trailing rule moves the floor to $49,800. If the balance then falls back to $50,000, the floor stays at $49,800, so the room you have left is $200, not $2,000.
Trailing vs static drawdown, end of day vs intraday
The same account and highs give three different floors. A static drawdown ignores your profit. An end-of-day trailing drawdown follows your best close. An intraday trailing drawdown follows your best moment, including open profit you never banked.
Firms differ on which rule they use, sometimes on different accounts at the same firm. The end-of-day vs intraday drawdown post shows how the same two trades pass under one rule and fail under the other. Always read the rules page for your specific account.
Where the trailing drawdown stops
Many accounts stop the floor at the starting balance. On this account that happens once the peak reaches $52,000: from there the floor stays at $50,000 however high the balance goes. Without that stop, a $54,000 peak would put the floor at $52,000 instead of $50,000. The checkbox in the calculator switches between the two.
Prop firm consistency rule calculator
Best day share = Best day ÷ Total profit
A consistency rule caps one day at a share of your total profit. Say the limit is 50%, you have made $2,000 and your best day was $1,700. That day is 85% of the total, so the rule fails. Keeping the same best day, total profit has to reach $1,700 ÷ 0.5 = $3,400, which is $1,400 more. The other way to pass is to stop one day carrying the account, which is also the better habit.
Firms differ on what counts as total profit, which days are included, and whether a breach fails you or raises your profit target. The calculator uses the plain version, best day over total profit, so check your firm's definition before relying on a pass.
Size trades against the floor, not the balance
Your real risk budget is the distance to the floor. Feed that number to the position size calculator to turn it into contracts, and check the reward-to-risk of the setup with the risk-reward ratio calculator. The sizing logic is in how much to risk per trade. The methods behind these figures are on the methodology page.
Track the floor on every trade
Doing this by hand means re-entering your high every session. ExpectancyIQ tracks drawdown and consistency against your account's rules automatically in the prop trading journal: set the rule once and the Risk and Discipline tab checks every imported trade, as part of your trading dashboard. This page is educational, not financial advice, and firm rules change, so confirm them with your firm.