Prop Firm Position Size Calculator

Enter your balance, the percentage you want to risk and the distance to your stop loss to see the position size that keeps the loss to that amount. Choose forex for a size in lots, or futures for a number of contracts.

How position size is worked out

Position size starts from the amount you are prepared to lose if the stop loss is hit. On a $100,000 account, risking 0.5% means a loss of $500.

For forex, divide that amount by the stop distance in pips multiplied by the pip value of one standard lot. With a 20 pip stop on EUR/USD, where one standard lot is worth about $10 a pip, the size is $500 divided by $200, which is 2.5 lots.

For futures, divide the amount by the stop distance in ticks multiplied by the tick value, and round down to whole contracts. One ES contract on the S&P 500 moves $12.50 a tick, so with a 16 tick stop one contract risks $200 and $500 allows two contracts. The micro contract, MES, moves $1.25 a tick, which allows finer sizing: the same stop and risk allows 25 micro contracts.

Choosing the risk per trade

The right risk per trade depends on how much room the account has. A common approach is to size each trade so that a run of losing trades cannot reach the daily loss limit. With a $5,000 daily limit and $500 risked per trade, it takes ten losses in a row to breach the limit in one day. The drawdown calculator shows how much room you have now.

Some firms also cap the risk on a single trade or the size of a position. Read maximum risk per trade rules before you size up, and see how professional traders manage risk inside funded accounts.

Pip and tick values

A standard lot is 100,000 units of the base currency. For pairs quoted in US dollars, such as EUR/USD and GBP/USD, a pip is worth $10 per standard lot. For other pairs the pip value moves with the exchange rate, and for gold and indices it depends on the contract size your firm’s platform uses, so check the symbol specification on your platform before you trade. Futures tick values are fixed in each contract’s specification.

The calculator is a guide only. It does not include spreads, commissions or slippage, which can make a loss slightly larger than planned.

Frequently Asked Questions

What is a pip value?

A pip is the fourth decimal place in most currency pairs, or the second in pairs quoted in Japanese yen. The pip value is how much one pip is worth for a given position size. For a standard lot of a pair quoted in US dollars it is $10, for a mini lot $1 and for a micro lot $0.10.

Why does the calculator round futures contracts down?

Futures trade in whole contracts, so the calculator rounds down to keep the loss at or under the amount you chose. If the result is zero, even one contract would risk more than that amount with your stop. A micro contract, where the market has one, lets you trade the same market with a tenth of the risk.

Should I risk the same amount on every trade?

Many traders keep risk per trade fixed as a percentage, so losses shrink as the account falls and grow as it rises. In a prop firm account the loss limits are fixed amounts, so it also helps to check the room left before each trade. The drawdown calculator shows that room for your firm’s rules.

Does position size change the profit target?

No. The profit target is set by the firm as a percentage of the starting balance. A larger position reaches it in fewer winning trades but also reaches the loss limits in fewer losing trades. Keeping the loss limits well out of reach usually matters more than reaching the target quickly.