Position Size Calculator
Enter your balance, the percentage you're willing to risk, and your stop distance — and get the exact lot size that keeps every trade the same controlled fraction of your account.
- Free — no login
- Deterministic engine
- No signals, no advice
Map.Trade does not provide buy/sell signals, execute trades, or manage funds. It helps traders review historical performance, risk, and behavior.
Position sizing is the one risk decision you can make perfectly, every time, before the trade. This calculator turns "how big should this one be?" into a fixed rule: risk the same small percentage of your account, sized precisely to your stop.
How to use it
- 1Enter your inputs
Balance, risk %, stop in pips, and the instrument you're trading.
- 2Read the size
Get the lot size that makes a full stop-out equal your chosen risk.
- 3Plan the trade
Place the trade at that size with your stop where you planned it.
- 4Review it later
Import the trade into Map.Trade and check planned vs actual risk.
How the position size calculator works
The formula
Pip value is derived from the instrument's contract size and pip size. When the pair's quote currency differs from your account currency, the result is shown as indicative — we never invent a live rate.
Worked example
Sizing inside a prop account
Common position-sizing mistakes
- Trading a fixed lot size regardless of how far away the stop is.
- Widening the stop after entry so the "planned" risk quietly doubles.
- Sizing to the account you wish you had instead of the one you're trading.
- Forgetting that JPY pairs, metals, and indices have different pip values.
Plan your size vs. size by feel
Who it’s for
Keep every intraday trade the same controlled risk across pairs and sessions.
Size so a normal losing streak can't threaten a daily or max-loss limit.
Translate wider stops into correct lot sizes without over-leveraging.
Plan the size here — review the result in your workspace.
Map.Trade does not provide buy/sell signals, execute trades, or manage funds. It helps traders review historical performance, risk, and behavior.
Frequently asked questions
How is position size calculated?
Risk amount = balance × risk%. Lot size = risk amount ÷ (stop in pips × pip value per lot), snapped to the instrument's lot step and clamped to its min/max.
What risk percentage should I use?
Many traders cap per-trade risk at roughly 0.5%–2% of the account; lower is more conservative. This is general education, not personalised advice — choose what fits your own plan and rules.
Does this support prop accounts?
Yes. Size to a fixed % first, then cross-check the result against the Prop Risk Calculator's remaining daily-loss room so a single trade can't breach a limit.
Why is my result labelled "indicative"?
When the pair's quote currency differs from your account currency and there's no exact conversion basis, we mark the value indicative rather than fabricate a live exchange rate.
Does it work for indices, metals, and crypto?
Yes — each instrument carries its own contract size and pip/point convention, and the calculator applies them.
Is this financial advice?
No. It is a deterministic calculator for planning and review. Map.Trade gives no buy/sell signals and no financial advice.
Related pages
Ready to review before you trade again?
Map.Trade does not provide buy/sell signals, execute trades, or manage funds. It helps traders review historical performance, risk, and behavior.