Crypto Position Size Calculator
Risk-based sizing · Perpetual futures · Never over-leverage
Calculate the correct position size from your maximum acceptable loss.
Position Side
How to use the position size calculator
- Enter your account balance in USDT.
- Set your risk percentage — the maximum you are willing to lose on this trade (recommended: 1–2%).
- Enter your entry price and stop loss price.
- Read the recommended position size — opening a position larger than this risks more than your limit.
Position size formula (risk-based)
The correct position size ensures your stop loss triggers before you lose more than your predefined risk amount:
- Max loss = accountBalance × riskPercent / 100
- Stop distance = |entryPrice − stopLossPrice| / entryPrice
- Position size = maxLoss / stopDistance
Position size is in notional USDT value (not margin). If your exchange uses leverage, the margin required = positionSize / leverage.
Worked example — SOL long, 1% risk
- Account: $5,000 · Risk: 1% · Entry: $150 · Stop loss: $142 · Leverage: 5×
- Max loss = $5,000 × 1% = $50
- Stop distance = ($150 − $142) / $150 = 5.33%
- Position size = $50 / 0.0533 = $938 notional
- Required margin = $938 / 5 = $187.50
You open a $938 SOL position using $187.50 in margin. If SOL drops to $142, your loss is exactly $50 — 1% of capital. Without position sizing, traders often size by margin and accidentally risk 10–20% per trade.
Why the stop loss comes first
Position sizing is the opposite of how most beginners approach trading. Most traders decide how much to trade, then set a stop. The correct order: decide maximum acceptable loss → find a technically valid stop loss level → calculate position size from those two inputs. This separates risk management from price prediction and keeps losses consistent regardless of volatility.
Run a full pre-trade risk check
Position size is one input. Before opening a trade, combine it with liquidation distance and funding cost in a single workflow:
Run Pre-Trade Risk Check →Use via API or MCP
Every calculation on this page is available as a deterministic API call. Plug exact position sizes into trading bots, risk dashboards, or AI agents — no approximations, no rounding surprises.
Frequently Asked Questions
What is position sizing in crypto trading?
Position sizing determines how much of your capital to risk on a single trade. Proper sizing protects your account from large losses. Most professional traders risk 1-2% of capital per trade.
How do I calculate position size from risk?
Divide your max acceptable loss by the distance to your stop loss (as a fraction of entry price), then multiply by leverage. This calculator does it automatically.
What's the 1% rule in trading?
Never risk more than 1-2% of your total capital on a single trade. If your account is $10,000, maximum loss per trade = $100-200. This rule preserves capital during losing streaks.
How does stop loss distance affect position size?
A tighter stop allows a larger position for the same risk amount. A wider stop requires a smaller position. Always set stop loss first, then calculate position size.