Position size calculator

What the number means

The calculator answers one question: how large can this position be so that, if the stop is hit, you lose the amount you planned to risk and nothing more. It is risk working backwards into size - not a prediction, not a recommendation to trade.

Size falls as the stop widens. A wider stop is not more cautious; it is the same risk spread over more distance, which forces a smaller position. If the suggested size looks too small, the honest reading is that the stop is too wide for the risk you can afford.

When your account currency differs from the pair's quote currency, one pip is worth a different amount to you than to a trader in the quote currency. That is what the conversion rate field handles - without it the size can be wrong by tens of percent.

Worked example

A £10,000 account risks 1% on GBPUSD with a 25 pip stop. One US dollar is worth £0.80.

• Cash at risk: £10,000 × 1% = £100.00
• Pip value for one standard lot: $10 × 0.80 = £8.00
• Risk per lot over 25 pips: 25 × £8.00 = £200.00
• Position size: £100 ÷ £200 = 0.50 lots, which is 50,000 GBP of GBPUSD

If price falls 25 pips to the stop, the position loses £100 - the 1% chosen at the start. The unit test suite pins these exact figures, so the copy and the calculation cannot drift apart.

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<iframe src="https://ticksprout.com/tools/position-size?balance=10000&currency=GBP&risk=1&stop=25&pair=GBPUSD&rate=0.8&embed=1" width="100%" height="700" style="border:0" title="Position size calculator" loading="lazy"></iframe>
<a href="https://ticksprout.com/tools/position-size">Position size calculator by Tick Sprout</a>

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