Forex Position Size & Lot Size Calculator
This position size calculator converts a cash-risk limit into an estimated number of standard lots and currency units. It is useful before an order is placed because it starts with the amount you can afford to risk rather than an arbitrary lot size. Enter the pip value that applies to your instrument and account currency; the common USD 10 per pip assumption is only a default for one standard lot in many USD-quoted major currency pairs.
Updated September 21, 2026 · Inputs stay in your browser
Educational estimate only. Confirm instrument specifications, live conversion rates, fees, margin rules, and order details with the relevant regulated provider.
Formula and assumptions
Cash risk is account balance multiplied by risk percentage. Currency units are estimated as standard lots multiplied by 100,000. Mini, micro, CFD, futures, and broker-specific contract sizes may use different unit conventions, so the contract specification remains authoritative.
How to use the calculator
- 01Enter the current account balance in your account currency.
- 02Choose the percentage of the account allocated to the trade idea. This is a maximum-loss input, not a profit target.
- 03Enter the distance between the intended entry and stop-loss price in pips.
- 04Enter the pip value for one standard lot in the account currency, then compare the result with the broker’s contract specification and minimum lot increment.
How to interpret the result
- Estimated cash risk shows the balance multiplied by the selected risk percentage.
- Estimated standard lots show the theoretical size before rounding to the venue’s permitted increment.
- Estimated units use 100,000 units per standard forex lot; this convention does not apply to every CFD, future, crypto asset, or metal contract.
Worked example
For a 10,000 account, 1% risk equals 100 of cash risk. With a 50-pip stop and a pip value of 10 per standard lot, the theoretical size is 0.20 lots, or about 20,000 units. If the venue accepts only 0.10-lot increments, the trader must round deliberately and recalculate the resulting risk.
Limits and risk controls
- The calculation does not include spread, commissions, financing, slippage, gaps, partial fills, currency conversion charges, or stop-order execution risk.
- Pip value changes when the quote currency and account currency differ. Use a current conversion factor or a value supplied by the trading venue.
- A stop price does not guarantee the exit price. In fast or illiquid markets, realized loss can exceed the amount estimated here.
These tools provide educational estimates, not investment, legal, tax, or risk-management advice. Leveraged products can produce losses greater than the amount initially deposited. Confirm every result with the provider’s live order ticket, contract specification, account agreement, and applicable rules.