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Forex Lot Size Calculator

Work out forex lot size instantly with clear inputs, formula shown and shareable results.

About Forex Lot Size Calculator

Lot size follows from risk, stop distance and pip value: the amount you are willing to lose divided by the loss per lot if the stop is hit. A wider stop therefore forces a smaller position, keeping risk constant.

Formula

Lot size

Lots = (balance × risk %) / (stop in pips × pip value per lot)

Worked example

With the default values below, Forex Lot Size Calculator returns Standard Lots To Trade of 0.221. Change any input above and every figure here is recalculated in your browser.

Inputs used

Account Balanceminimum 0
500,000
Risk Per Tradeaccepts 0.05–20 %
1.5 %
Stop-Loss In Pipsaccepts 1–2,000
40
Pip Value Per Standard Lotminimum 0
850

Results

Standard Lots To Trade
0.221
Amount At Risk
$7,500.00
Position Size In Units
22,059
Risk Per Pip
$187.50

Step by step

  1. 1Values used
  2. 2Lot size
  3. 3Standard Lots To Trade= 0.221
  4. 4Amount At Risk= 7,500.00
  5. 5Position Size In Units= 22,059
  6. 6Risk Per Pip= 187.50

Assumptions and limits

  • The result is derived only from the 4 inputs listed above. Anything not among them is not part of the calculation.
  • In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
  • Figures are rounded for display to 3 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
  • Figures are estimates for planning only. Market returns are not guaranteed, and rates, limits and tax rules change. This is not financial or tax advice — speak to a qualified adviser before acting.
  • This is an estimate for general information and not professional financial, tax or legal advice. See the full disclaimer for the limits that apply to this kind of calculator.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Figures are estimates for planning only. Market returns are not guaranteed, and rates, limits and tax rules change. This is not financial or tax advice — speak to a qualified adviser before acting.

Frequently Asked Questions

Why fix risk rather than lot size?

Fixed risk keeps every trade's impact on the account equal, which is what makes a losing streak survivable.

Does leverage decide position size?

No. Leverage sets the margin needed; risk and stop distance should set the size.

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Forex Lot Size Calculator – Calculate Standard Lots To Trade