Crypto position size calculator
Position size = the amount you are willing to lose ÷ the share of the position you lose if your stop is hit. Risking 1% of a 50 SOL portfolio with a 20% stop gives a position of about 2.3 SOL after fees.
- Loss if the stop is hit
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- Fees inside that loss
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- Profit at target, after fees
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- Reward to risk
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| Losses | Portfolio left | Share |
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How position size is calculated
Example: a 50 SOL portfolio and 1% risk means you accept losing 0.5 SOL. With a 20% stop and a 1% fee on the buy and on the sell, each SOL in the trade loses 1 − 0.9801 × 0.8 = 0.2159 SOL when the stop is hit. After 0.002 SOL of priority fees, (0.5 − 0.002) ÷ 0.2159 = 2.31 SOL.
Without fees the same inputs give 2.5 SOL. Fees are part of the loss, so counting them makes the position slightly smaller.
The losing-streak table assumes every trade risks the same share of whatever is left in the portfolio. It shows why small fixed risk survives long streaks: at 1% per trade, 20 losses in a row still leave about 82%.
Questions
How much should I risk per trade?
There is no single right number. A fixed share of 1% to 2% per trade is a common rule in trading books, because a long losing streak then leaves most of the account intact. This is general information, not advice.
Will my stop-loss fill at the price I set?
Not always. A stop on a trading terminal is a triggered order: the sale is sent when the price reaches your level. In a fast drop or a thin pool it can fill well below that level, so the real loss can be larger than planned.
Why do fees change the position size?
You pay the platform fee on the buy and again on the sell, plus priority fees. Those costs are part of what you lose when a trade is stopped out, so the position has to be a little smaller to keep the total loss at your limit.
Last updated November 2026.