§ POSITION SIZING
Size the trade before you take it.
Most blown accounts aren’t a strategy problem — they’re a sizing problem. Postmortem’s position size calculator turns your risk tolerance into an exact position, leverage- and direction-agnostic, so the fat-fingered 20× “oops” never reaches the exchange.
§ FREE CALCULATOR · NO LOGIN
Size a trade right now
Everything runs in your browser. Prices are USDT-quoted; nothing is sent anywhere.
POSITION SIZE
— coins
— notional
- Risk amount
- —
- Stop distance
- —
- Margin used
- —
§ IF IT KEEPS GOING WRONG
- Losses to −50%
- 69 in a row
- Losses to −90%
- 230 in a row
Full-risk losses, compounding. The math is patient; tilt isn't.
Risk-based sizing in two numbers
Give it your capital and the percentage you’re willing to lose. Enter your entry and stop price. It returns the position size in USDT and coins, the required margin at your leverage, and the exact risk amount — so every trade risks the same slice of your account regardless of how far the stop is.
The math is identical across the web and mobile app, so your numbers agree to the centavo.
See the cost of tilt before it happens
The calculator also shows how many consecutive full-risk losses would take your account to −50% and −90%. At 1% risk that’s dozens of trades; at 5% it’s a handful. Seeing the compounding math is the fastest cure for oversizing.
A LONG/SHORT toggle and a wrong-side-stop warning keep you honest about direction.
FAQ
What’s the position-size formula?
risk_amount = capital × risk%; stop_distance% = |entry − stop| / entry; position = risk_amount / stop_distance%. It’s leverage- and direction-agnostic.
Is the calculator free?
Yes — position sizing is available on the Free plan.
Related reading
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