Position Size Calculator
Position size is the one input that decides whether a losing streak is survivable. Enter your account size, the percentage you’re willing to risk, and where your stop goes — this returns the size that keeps that risk fixed, and shows the arithmetic.
Most risk frameworks cap this at 1–2%.
Where your idea is wrong — not where the loss feels tolerable.
Position size
0.50
standard lots
Units
50,000
of EUR
At risk
$100.00
if the stop is hit
Show the arithmetic
Risk amount = $10,000.00 × 1% = $100.00
Pip value = 0.0001 × 100,000 units = 10 USD per standard lot (no conversion needed — quote currency matches your account)
Lots = $100.00 ÷ (20 pips × $10.00) = 0.5000
One pip on this position = $5.00
Position sizing controls how much you lose when you are wrong. It does not make a losing strategy profitable, and it is not a prediction about any trade.
How the calculation works
Three numbers decide your position size, and none of them is a prediction about the market:
- Cash at risk — your balance times the percentage you’re prepared to lose on one idea.
- Stop distance — how far price has to move against you before the idea is wrong, measured in pips.
- Pip value — what one pip is worth per standard lot on the pair you’re trading. See the pip value calculator.
Divide the cash at risk by the stop distance times the pip value, and you have your size. That is the whole formula. Everything else people sell you on top of it is decoration.
Why we don’t fetch live exchange rates
When your account currency differs from the pair’s quote currency, converting the pip value needs an exchange rate. We ask you for it rather than fetching one. A rate that is minutes stale produces a position size that is quietly wrong, and unlike most wrong numbers on the internet, this one costs money. Take the current rate from your broker’s platform — the same place your trade will actually fill.
What this does not do
Position sizing controls the size of your losses. It does not turn a losing strategy into a profitable one, it does not account for slippage or gaps past your stop, and it is not a recommendation to take any trade. If the answer looks uncomfortably small, that is the calculation working.
The risk worksheet that goes with this
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