Crypto & perps position-size calculator
What position size fits my stop loss and risk budget?
Divide your loss budget by the distance from entry to stop, then check the position against your available margin and leverage.
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Available margin is the amount free for this trade. Enter the leverage allowed on your market. Quote updates never change your chosen entry or stop.
Enter an entry and stop price to calculate your size. All fields are required.
Margin allocation is not risk percentage.
Using 25% of buying power does not mean risking 25% of your account. Risk depends on quantity and distance to your stop. Raising leverage changes required margin, not P&L at a fixed quantity.
One unit = 1 BTC. Linear USD-priced perps only. Estimated stop loss excludes fees, funding and slippage; a stop does not guarantee its fill price. Quantity is theoretical—round down to your venue’s size increment. This does not check liquidation, firm drawdown rules or position caps.
Position size = loss budget ÷ stop distance
Illustrative example: a $100 loss budget, $80,000 BTC entry and $79,000 stop gives 0.1 BTC. That is $8,000 of exposure and $800 of margin at 10×. With only $500 available margin, size falls to 0.0625 BTC and estimated loss at the stop falls to $62.50.
Why is my size below the risk-based amount?
A tight stop can imply more exposure than your buying power supports. This tool uses the smaller of your risk-based size and your available margin × leverage ÷ entry price.
Does 10× leverage mean ten times the stop loss?
Not when quantity is fixed. A 0.1 BTC position loses $100 on a $1,000 adverse move at any leverage. More leverage reduces its initial margin requirement; it can also allow you to choose a larger, riskier position.
Where does the reference price come from?
The tool requests Hyperliquid’s public perp mark price. Click to use it or enter your planned entry manually. It may differ from your firm’s fill price. The shown time is when the quote was fetched.
Hyperliquid public API documentation