The calculator does one job: convert a risk budget into a broker-enterable lot count for a given symbol. You give it entry, stop-loss, and either a percent of your capital (we read Settings → Capital) or an absolute amount. It looks up the symbol's contract size (100 000 for Forex, 100 oz for Gold, 1 for stocks and crypto), pulls the quote-to-account FX rate when the instrument is denominated in a foreign currency, and returns both the *exact* lot count and the broker-friendly 0.01-step rounded value — plus the actual risk that rounding produces.
Direction is inferred from the stop placement: SL below entry → BUY, SL above entry → SELL. You can override the FX rate manually if you don't trust the live look-up — the rate the calculation used is always shown so there's never a hidden number.
EUR account, €7 600 capital, 0.5 % risk = €38. Going long EURUSD at 1.0800 with a stop at 1.0750 (50-pip stop). EUR-to-USD rate ≈ 1.08.
Risk-percent presets (0.5 / 1 / 2 %) sit on top of the percent field for one-click sizing. Most disciplined retail traders stay between 0.25 % and 1 % per trade — at 2 % a six-trade losing streak already costs you 12 % of capital, and streaks of that length are statistically normal. Below 0.25 % the position is so small the result rarely covers fees on tight stops; above 2 % a single bad week can do durable damage.
Target vs actual. Because brokers only accept 0.01-step lots, the calculator surfaces two numbers: the risk you targeted (your budget) and the risk the rounded lots actually produce. They diverge by a few percent at most — useful to see, not something to optimise. If the gap matters for your account size, set the risk as an absolute amount instead of a percent and the result is exact by construction.
FX source flags. *live* — fetched from the last daily close (good enough for sizing). *manual* — you entered the rate yourself. *same* — the instrument is already in your account currency, no conversion needed. *assumed* — the quote currency is ambiguous (individual stock, exotic index) and we fell back to 1.0; trust the lots, but know the risk could be off by the prevailing FX move if the stock isn't in your account currency.
Use it before every entry. Position-sizing math feels small until the day the math is wrong — at 1 % per trade your spreadsheet error eats half your monthly progress in one click. The calculator removes the chance to fat-finger: enter the stop, choose the risk percent, copy the rounded lots into the broker.
The page lives at Tools → Position Size in the dashboard. Your account currency and capital are read from Settings → Capital; if you keep multiple accounts (Pro Plus), switch the active account in the header before sizing — every account can have its own capital baseline.
The rounded lot count is the broker-ready value; the exact lot count below it is informational, showing how much the 0.01-step rounding nudged you. The FX-source line right under the result tells you whether the rate came from a live close, your manual override or a same-currency match — three different reasons to trust the number to different degrees.
This is a calculation tool, not investment advice. The lot size it returns is the mechanical answer to your inputs; whether the trade itself is a good idea is your call.