Position Size Calculator
Calculate the exact number of coins or contracts to buy based on how much of your account you are willing to risk on a single trade. Used by traders who follow strict risk management rules to avoid oversized losses.
About this calculator
Position sizing is a core risk management technique that ensures no single losing trade can devastate your account. The formula is: Position Size = (accountSize × riskPercent / 100) / |entryPrice − stopLossPrice|. The numerator is the maximum dollar amount you are willing to lose on the trade. The denominator is the per-unit dollar risk — the distance in price between your entry and your stop-loss. Dividing the two gives the number of units (coins or contracts) you can hold while keeping your loss exactly at your defined risk threshold if the stop is hit. If entry and stop-loss are the same price, position size is zero, which prevents a division-by-zero error. This method is often called the 'fixed fractional' position sizing approach.
How to use
You have a $10,000 account and are willing to risk 2% per trade. You plan to buy ETH at $2,500 with a stop-loss at $2,400. Step 1 — Dollar risk: $10,000 × 0.02 = $200. Step 2 — Price distance: |$2,500 − $2,400| = $100 per ETH. Step 3 — Position size: $200 / $100 = 2 ETH. You buy exactly 2 ETH. If the stop-loss triggers at $2,400, you lose $200 (2%), keeping your account intact for the next trade. Enter these values and the calculator returns 2 ETH instantly.
Frequently asked questions
What percentage of my account should I risk per crypto trade?
Most professional traders risk between 1% and 2% of their account per trade. At 1% risk, you would need 100 consecutive losing trades to lose your entire account, giving your strategy ample time to play out. Risking 5% or more per trade can lead to severe drawdowns from short losing streaks, which are statistically normal even for profitable strategies. Beginners are often advised to start at 0.5–1% until they have validated their edge.
How does my stop-loss distance affect my position size in crypto?
The wider your stop-loss, the smaller your position size, and vice versa. A tight stop-loss (small price distance) allows a larger position for the same dollar risk, while a wide stop-loss forces a smaller position. This is important in crypto because arbitrarily tightening a stop-loss to hold more coins does not reduce risk — it only increases the likelihood of being stopped out by normal volatility. Your stop-loss should be placed at a technically meaningful level first, and then position size should adjust accordingly.
Why is position sizing more important than entry timing in crypto trading?
Even the most precise entry can result in account ruin if position size is uncontrolled. Conversely, a mediocre entry combined with disciplined position sizing limits losses to a manageable amount, preserving capital for future opportunities. Many traders who blow up their accounts do so not because of bad entries but because they risked too much on a single trade. Consistent position sizing ensures that your long-term profitability is determined by your win rate and risk-to-reward ratio, not by luck on any individual trade.