Trailing Drawdown Calculator
A trailing drawdown floor rises with every new equity peak and never falls back — the single mechanic most free calculators skip because it is harder to model than a fixed floor. This page derives the arithmetic, then hands you a live simulator for your own maximum-drawdown allowance.
Max Drawdown in this widget is a static floor from starting balance (v1) — a fixed floor measured from your starting balance, not a floor that ratchets upward with a new equity peak. Paths below are counted against this static floor from starting balance. At equal allowance a trailing floor is never easier (F = M − A); this widget does not apply that ratchet — run a named firm for that firm's published floor.
Max drawdown you allow is the floor the simulation checks every simulated trade against — read the honesty note above before treating the result as a specific firm's own trailing math.
Same engine at the same free accuracy — save a rule set, add a stop, or import a history. The stamped file is written after that run, not from this typed-average result.
The mechanism
A trailing drawdown floor is F = M − A, where M is the account's high-water mark (the highest equity it has ever reached) and A is the stated allowance. Because M is a running maximum, F only ever rises — a trailing floor is a ratchet, not a fixed line. The breach condition, M − E ≥ A (current equity E has fallen at least A below the peak), never references the starting balance at all, which is what makes a trailing floor behave so differently from a static one.
Worked example — a $50,000 account, a 5% allowance ($2,500), peaking at $53,600 before giving profit back:
| Quantity | Formula | Value |
|---|---|---|
| Allowance | balance × 5% | $2,500 |
| Floor at peak | peak − allowance | $53,600 − $2,500 = $51,100 |
| Standing profit at the peak | peak − balance | $3,600 |
| Profit remaining if eliminated at the floor | floor − balance | $1,100 |
The account can be eliminated at $51,100 — which is still $1,100 above the $50,000 starting balance. "Profitable" and "alive" are independent states once the floor has ratcheted past the starting balance; this is proven, not asserted, in the full derivation at Trailing drawdown, explained, which also proves the strict ordering intraday-trailing ≥ end-of-day-trailing ≥ static for the same allowance and the same trading.
What the calculator above actually models — read this before trusting the number
The free personal-rule engine currently models a stated Max Drawdown allowance as a fixed floor measured from your starting balance, not a floor that ratchets upward with a new equity peak. Concretely: the floor above (F = M − A) never appears in the calculator's v1 — it applies your allowance to your starting balance and leaves it there, the same way every free "your own rules" run on this site currently does (the widget's own source sets ddMode: "static" directly, marked as a v1 limitation, not a design choice).
The survival percentage the calculator reports is the static-floor count (ddMode: "static"). At equal allowance a trailing floor is never easier — F = M − A does not run in this widget. The gap between the two is exactly what the static-vs-trailing drawdown study measures firm by firm, with a published, reproducible dataset. To apply a firm's published ratchet, run a named firm — the firm rules index lists every mechanic PropSurvival's corpus has verified, and the simulator applies each firm's own published rule set, ratchet included, without the static-floor substitution described here.
The full tool that applies a named firm's published trailing mechanic, without the static-floor substitution above, is the prop firm simulator.
FAQ
- What is a trailing drawdown?
- A drawdown floor that ratchets up with every new equity high-water mark and never moves back down — the breach condition is (peak equity − current equity) ≥ allowance, which never references the starting balance once the peak has moved past it.
- How is a trailing drawdown different from a static drawdown?
- A static floor is fixed relative to the starting balance and never moves; a trailing floor rises with every new peak. For the same allowance and the same trading, a trailing floor is proven to be at least as hard to survive as a static one, never easier: F = M − A, so the floor can sit above start and eliminate an account that is still green.
- Does this calculator model a real trailing floor?
- No — the live calculator above uses the free personal-rule engine, which currently applies a stated maximum-drawdown allowance as a static floor from the starting balance (v1; trailing support for self-defined rules is a later engine version). It counts paths against a static floor from starting balance. It does not apply F = M − A. Running a specific firm in the simulator applies that firm's actual trailing mechanic, unmodified.
Run it against your own numbers
The same engine, unlimited runs, at the same free accuracy as this page's calculator — open the full personal rule editor to save a rule set, add a profit goal or daily loss stop, or import a trade history.
Open the personal rule editor — free, full accuracy →Rules and outcomes vary by firm and by trader; nothing on this page is investment or trading advice, and PropSurvival is not affiliated with, endorsed by, or sponsored by any prop trading firm. This calculator models a stated rule set — it does not predict market outcomes.