Free calculator
Position size calculator
Enter your account size, how much of it you are willing to lose, your entry and your stop. You get the position size, the margin you post and, if you use leverage, a liquidation check.
Position-size calculator
EstimateThe example is a $10,000 paper account risking one percent, with the stop 2% below the entry. Change any number.
Fix the highlighted field to see the result.
Size comes from the stop: risk amount divided by the distance to the stop. Before fees and slippage, which make a real loss slightly bigger than planned. The liquidation check uses a 0.5% maintenance margin, and exchanges calculate it differently.
How it works
Size comes from the stop, not from how sure you feel about the trade. Four steps:
- Risk amount = account × risk per trade. $10,000 × 1% = $100.
- Stop distance = entry − stop. $60,000 − $58,800 = $1,200 per coin, a 2% move.
- Position size = risk amount ÷ stop distance. $100 ÷ $1,200 = 0.0833 BTC, worth about $5,000.
- Margin = position value ÷ leverage. With no leverage you pay the full $5,000. At 5x you post $1,000.
If price hits the stop you lose about $100, whichever leverage you use. Fees and slippage make the real loss slightly bigger.
Why one percent
Losing streaks happen to every trader. At 1% a trade, ten losses in a row cost about 9.6% of the account. At 5% a trade, the same streak costs about 40%, and you then need a 67% gain just to get back to where you started.
Leverage doesn't change your risk
Leverage changes how much margin you post, not how much you lose at the stop. What it does change is where liquidation sits. If the liquidation price is closer than your stop, you are closed out before the stop can do its job, so the calculator warns you. The liquidation price calculator shows the full picture.
Common questions
What if the position comes out bigger than my account?
A tight stop can call for a position larger than the account, which would need leverage. Your loss at the stop stays the same, but liquidation moves closer, so check it sits beyond your stop. Often the better answer is a stop at a level that really proves the idea wrong, and a smaller position.
Should I risk 1% or 2%?
One percent is the rule Bentley Academy uses, and a common starting point. Some traders go up to 2%. Above that, an ordinary losing streak does serious damage to the account.
Does it work for shorts?
Yes. Pick Short and put the stop above the entry. The math is the same.