How to use the Prop Firm Drawdown Calculator
- Enter starting balance, current equity, and day-start equity.
- Set the daily and max loss limits from your rulebook.
- Choose whether the max rule is static or trailing.
- Enter the high-water mark for trailing models.
- Use a safety buffer so your plan does not sit exactly on the breach line.
Formula
Daily floor = Day start equity x (1 - Daily limit %)
Static max floor = Starting balance x (1 - Max limit %)
Trailing max floor = High water mark x (1 - Max limit %)
Usable room = min(Daily room, Max room) - Safety bufferExample
On a $100,000 account with a 5% daily rule, day-start equity of $100,000 creates a daily floor of $95,000 before any safety buffer.
What to watch
- Prop-firm rules differ. Always compare the calculator model to the exact rulebook.
- Some firms use balance, some use equity, and some update trailing thresholds intraday or at end of day.
- The safest output is the nearest breach equity plus a buffer, not the absolute last dollar.
Frequently asked questions
What is daily drawdown room?+
It is the amount current equity can fall before reaching the daily loss floor, after any safety buffer.
What is trailing drawdown?+
A trailing rule moves the breach floor upward as the account reaches new highs.
Why include a safety buffer?+
Spreads, commissions, slippage, and platform timing can push equity past a rule faster than clean math suggests.