Position Size Calculator Pro: Stocks, Crypto, Forex, Futures

Size every trade so a stop-out costs what you planned. Stocks, crypto perps, forex and futures, right in your toolbar. Position Size Calculator is a fast, private calculator for traders. Enter your account, your risk and your entry and stop. It tells you exactly how many shares, coins, lots or contracts to trade, rounded down so you never risk more than your budget. FREE FOREVER: STOCKS - Shares to buy or short from account equity and risk % or fixed $ - $ at risk, position value, margin warning - Breakeven and total loss including commission - R-multiple of your target and a 1R / 2R / 3R ladder - Whole or fractional shares, one-click summary PRO (7-DAY FREE TRIAL, NO CARD NEEDED) - Crypto perpetuals: coin size with taker fees and slippage on both fills, margin at your leverage, an estimated liquidation price, and a warning when liquidation comes before your stop (with the highest safe leverage) - Forex: lots and units for any pair, JPY pip handling, automatic conversion when your account currency is in the pair, spread and commission per lot - Futures: built-in specs for ES, MES, NQ, MNQ, CL, MCL, GC, MGC (or enter your own tick size and value), slippage ticks, commission, margin, and a hint to use the micro when one contract is too big - Fees and slippage included in the size, not added afterwards - Presets: save your usual contract, leverage, fees and risk - Daily loss-limit guard: set your limit and today's P/L, and Pro warns you when this trade's loss would break the limit and tells you the largest size that fits. You also set a max number of trades per day. - Trade history with CSV export. Columns match our Trading Journal + Risk OS spreadsheet, so plans paste straight into your journal. HOW THE MATH WORKS Risk budget = equity x risk % (or fixed $). Loss per unit = (entry fill - stop fill) plus fees on both sides plus slippage. Size = budget / loss per unit, rounded down to your size step. Crypto liquidation estimate (isolated, linear perps) = entry x (1 - 1/leverage + maintenance margin) for longs and entry x (1 + 1/leverage - maintenance margin) for shorts. Every formula is checked against hand-worked examples. PRIVATE BY DESIGN - Calculations run on your device. No account with us, no tracking, no ads, no analytics. - The only network request is the Pro license check: your license key goes to Gumroad (api.gumroad.com) to confirm the purchase. Nothing else ever leaves your browser. - Permissions: storage, and access to api.gumroad.com only. It cannot read the websites you visit. GET PRO Buy a license on Gumroad (link inside the extension), then paste the key into Settings. Your trial and Stocks keep working without one. IMPORTANT This calculator is an educational tool, not financial advice. Trading carries a high risk of loss, and leveraged products can lose more than your stop suggests. Fee, slippage and liquidation figures are estimates. Real fills, funding payments, gaps and exchange rules vary, and a stop-loss order is not guaranteed to fill at your price. Check with your broker or exchange before you trade.