Why lot size matters
Lot size is the difference between controlled risk and random risk. A 30-pip stop on EURUSD, a 10-tick stop on ES, and a $100 move on BTCUSD all mean different dollar amounts. This calculator turns your stop-loss distance and risk percentage into the position size that matches your plan.
Position size formula
Position Size = (Account Balance × Risk %) ÷ (Stop-Loss Distance × Pip/Tick Value)
The calculator first works out your dollar risk, then divides it by the amount you lose per pip or tick if price hits your stop. Futures are rounded to whole contracts; forex and most CFDs are rounded down to common 0.01 lot increments.
FAQs
How much should I risk per trade?
Many traders use 0.5% to 2% per trade. One percent is a common starting point, but the right number depends on your strategy, drawdown tolerance, and prop-firm rules.
Why is futures size rounded to whole contracts?
Exchange-traded futures do not trade in fractional contracts. If your calculated ES size is below 1 contract, try MES instead because micro futures have smaller tick values.
How do I know the stop-loss distance?
Use your chart setup first, measure entry to stop in pips/ticks, then enter that number here. For the dollar result of a pip or tick, use our pip value calculator.