Funding-Aware Position Size Calculator
Size a BTC, ETH or SOL USDT perpetual position after reserving expected holding-period funding costs within your stop-loss risk budget.
Your cash risk budget and holding period
Position size within one risk budget
Binance BTCUSDT — USDT linear perpetual.
Market snapshot: 2026-10-25 10:28:18 UTC.
Automatic entry: 80289.9 USDT / BTC; price source 2026-10-25 10:27:00 UTC.
Current funding: 0.00734500% per 8h equivalent — selected contract quote.
Enter an adverse stop-loss price and calculate. Correct any inline errors or supply the missing manual entry to see a result.
Automatic data requires a snapshot no older than 120 seconds, fresh fields and a price source timestamp no older than 120 seconds. Future timestamps are excluded. Missing or stale funding is never treated as zero; a fresh quoted zero is valid.
How funding changes your position size
The current rate (or your manual rate) and entry notional are held constant for the entire holding period. These are illustrative costs, not guaranteed future payments or maximum realized losses. Rates, settlement timing and position value can change; gaps, slippage and liquidation can produce larger losses.
Cash risk R = balance × risk percent / 100. Stop and trading fees per coin L = |entry − stop| + fee × (entry + stop), where fee is the per-side fraction.
Signed funding per coin F = side sign × entry × rate per 8h × 3 × days, where the rate is a fraction and side sign is +1 for long, −1 for short.
Price/fee-only quantity R / L. Funding-reserved quantity R / (L + max(F, 0)). Funding income never enlarges the trade.
Example: a 100 USDT risk budget, entry 100, long stop 90, zero fees, 0.1% funding per 8h and a 7-day hold give L = 10 and F = 2.1 USDT per coin. Size falls from 10 to 8.26446281 coins: 82.64 USDT stop loss plus 17.36 USDT funding reserve equals the 100 USDT budget. With negative funding, size stays at 10 coins; fresh zero funding also leaves size unchanged.
USDT is treated as a USD equivalent; depegging is excluded. Quantities are illustrative and rounded for display, without exchange lot-size or margin checks. This calculator does not model liquidation, risk tiers or available collateral.