MT5 Position Size Calculator: Risk-Based Lot Size on the Chart
Correct position sizing is the foundation of risk management. Trade Assistant Risk Calculator calculates your lot size automatically from your account, risk percentage and stop-loss distance, right inside MetaTrader 5.
Buy on MQL5 MarketTry Free DemoThe position size formula
Lot size = (Account risk amount) ÷ (Stop-loss distance in pips × pip value per lot)
Example: with a $10,000 account risking 1% ($100) and a 25-pip stop on EURUSD (about $10 per pip per standard lot), lot size = 100 ÷ (25 × 10) = 0.40 lots. Doing this by hand for every setup is slow and error-prone, especially on gold, indices and crypto where pip values differ.
Automatic calculation in MT5
Drag the Stop Loss line and the EA recalculates lots instantly so your risk stays constant. Pick the risk basis that fits your plan:
- % Balance, % Equity, % Free Margin
- Fixed money or fixed lots
- % of a custom reference amount
- % of previous day, week or month balance
Commission-aware sizing
Enable commission-inclusive lot sizing and the EA deducts estimated round-turn commission from your risk budget, so the real net loss equals your target.
Spread filter and confirmation
Block entries when spread is too wide and review a Confirm Trade dialog showing lots, risk, margin, entry, SL and TP before sending.
Get your MT5 position size calculator
Full version works on live and demo accounts, with no time limit. Try the free 30-day demo first.
Buy on MQL5 MarketTry Free Demo