Position Size & Stop-Loss Calculator

How Position Size Is Estimated

The calculator first converts the risk percentage into a dollar risk budget. It then estimates the loss per unit from the entry-to-stop distance plus the fee and slippage assumptions you enter:

Risk budget = account equity × risk percentage
Estimated quantity = risk budget ÷ estimated loss per unit

For a hypothetical ,000 account with a 1% risk limit, the budget is 0. If entry is 0 and the stop is , the simple no-cost estimate is 20 units (0 ÷ ). A linear contract with a ,000 notional position would require about 0 initial margin at 10× leverage, before venue-specific rules. Leverage changes that margin estimate; it does not reduce the price loss on the same quantity.

Important assumptions

This simplified estimate assumes price moves linearly with quantity and that the stop fills at its trigger. Gaps, spread, partial fills, funding, contract multipliers, inverse contracts, and exchange fee schedules can change realized loss. The stop should come from a defensible invalidation level, not be moved solely to increase quantity. Compare with the liquidation price calculator and verify contract specifications with your venue. See our disclaimer and privacy notice.