How do I calculate lot size from risk?

Multiply your balance by your risk percentage to get the money at risk, divide by the stop distance in pips times the pip value per lot, and round down to your broker's order step.

Why is my position size rounded down?

Rounding to the nearest step can round up, which risks more than you set. A risk control that can exceed its own limit is not one.

Free calculator

Position size calculator

Position size is the amount you are willing to lose, divided by what one lot loses if the stop is hit. This calculator does that for forex, metals, indices and crypto, rounds down to the order step so the trade never risks more than you asked, and says when the smallest allowed order is already too large.

Last updated 30 September 2026.

Position size

MarketAccount balanceUSDRisk per trade%Stop distancepips

Position size0.40 lots

Loss if the stop is hit$100.00

That is, of the account1.00%

Rounded down to the order step, so it never risks more than you asked for.

Pip value used, per 1.00 lot$10.00

Pip values are from contract specifications read on 6 August 2026, for a US dollar account. They differ by broker, and for markets not quoted in dollars they move with the exchange rate. The terminal sizes every order from your own broker's live specification.

The arithmetic

01
Money at risk
Account balance multiplied by the share you chose to risk. One percent of 10,000 is 100.
02
Loss per lot
Stop distance in pips multiplied by the value of one pip on one lot of that market.
03
Lots
Money at risk divided by loss per lot.
04
Round down
Down to the broker's order step, never to the nearest. Rounding up would risk more than you set.

Where it goes wrong by hand

Pip value is not the same on every market. It depends on the contract size and on the currency the market is quoted in.
On a small account with a wide stop, the smallest order a broker accepts can already risk more than you intended. The calculator says so instead of quietly rounding up.
An account in a currency other than the one the pip value is quoted in needs converting. This page works in US dollars.

A calculator shows what follows from the numbers you enter. It is not a forecast and not personal financial advice. Trading carries risk and you can lose money.

Position size calculator

The arithmetic

Where it goes wrong by hand

More calculators

Questions worth asking.

The right size is arithmetic, not a feeling.