Position Size & Stop-Loss Calculator
Start with the loss budget and the stop. See the quantity that fits both your chosen risk and available capital, then check the effect of fees and a worse stop fill.
Your inputs
Editable hypothetical example. Prices and fees are assumptions, not live quotes or a forecast.
Long: stop below entry. Short: stop above entry. Slippage moves the assumed stop fill farther against you. An actual stop fill can be worse.
The capital cap covers purchase value or initial margin plus the entry fee. Enter a budget within account equity; reserve any extra cash your venue requires separately.
Use the venue’s asset quantity increment, if known. Size rounds down. Price ticks, minimum order value, funding, and margin tiers are not checked.
Your result
- Asset quantity
- 45.49590537
- Position value
- 4,549.59 USDT
- Chosen loss budget
- 100.00 USDT
- Estimated loss at stop
- 100.00 USDT
- Account risk (%)
- 1%
- Assumed stop fill price
- 98 USDT
- Entry-to-stop distance (%)
- 2%
- Purchase value + entry fee
- 4,554.14 USDT
- Net profit at target
- 263.60 USDT
- Net reward / risk
- 2.64 : 1
- Break-even win rate (%)
- 27.5%
Estimated stop loss includes entry and stop-exit fees. Target profit includes both fees, with no target slippage. Funding is excluded. A stop is not a guaranteed loss cap.
The break-even win rate assumes every trade ends at this target or this stop with these same costs. It is arithmetic, not an estimated chance of winning.
Calculation ledger
5| Calculation | Amount (USDT) |
|---|---|
| Price-move loss | 90.99 USDT |
| Entry fee | 4.55 USDT |
| Stop exit fee | 4.46 USDT |
| Estimated loss at stop | 100.00 USDT |
| Net profit at target | 263.60 USDT |
How this calculation works
The chosen loss budget is account equity multiplied by the entered risk percentage, or an entered cash amount. The assumed long stop fill is trigger × (1 − slippage); the short fill is trigger × (1 + slippage). Loss per unit adds the adverse price move, entry commission and stop-exit commission.
Risk allows quantity = loss budget ÷ loss per unit. Capital allows quantity = capital budget ÷ (entry ÷ leverage + entry fee per unit). The tool takes the smaller quantity and rounds down if an increment is supplied. Target reward subtracts entry and target-exit fees; net reward divided by estimated stop loss gives reward-to-risk.
Formula
risk budget = equity × risk %; quantity = min(risk budget ÷ loss per unit, capital budget ÷ opening cash per unit); stop loss = quantity × loss per unit
Worked example
With 10,000 USDT equity, a 1% loss budget is 100. At entry 100, stop 98, no slippage, and 0.1% entry and exit fees, loss per unit is 2 + 0.10 + 0.098 = 2.198. Unrounded risk size is about 45.495905 units, worth 4,549.59 USDT. A smaller capital budget or quantity increment reduces that size.
What to keep in mind
This is a planning calculation for spot buys and linear long or short positions. It excludes funding, inverse contracts, liquidation, maintenance tiers and exchange-specific fee reserves. Stop fills can exceed the entered slippage. A budget cap does not confirm order eligibility; check venue rules and available collateral before trading. The example risk percentage is an input, not a recommendation.