Position size equals risk budget divided by risk per unit

Start with an account-equity percentage or a fixed dollar budget. The calculator adds the entry-to-stop price gap to a reserve for fees and slippage. It then divides the risk budget by that combined amount for one unit of the asset.

risk_budget = account_equity × risk_percent ÷ 100
price_risk_per_unit = absolute(entry_price − stop_price)
reserve_per_unit = entry_price × reserve_bps ÷ 10,000
risk_size = risk_budget ÷ (price_risk_per_unit + reserve_per_unit)

In fixed-budget mode, the fixed amount replaces the first formula. For a long position, the stop must be below the entry. For a short position, the stop must be above the entry.

Leverage and collateral can set a lower size

Hyperliquid states that the margin required to open a perpetual position is position size multiplied by mark price, then divided by leverage. The page uses entry price as a planning value for notional. The live margin check can differ because Hyperliquid uses the current mark price and account state.

collateral_size = collateral_cap × maximum_leverage ÷ entry_price
maximum_size = minimum(risk_size, collateral_size)
notional = maximum_size × entry_price
estimated_initial_margin = notional ÷ maximum_leverage

Maximum leverage depends on the asset and its margin tier. Enter the lower of your own leverage limit and the current market limit. If you leave maximum leverage empty, the calculator uses 1× for the margin estimate and any collateral cap. The estimate uses your planning leverage. Hyperliquid's account-specific margin requirement can differ from the estimate.

A stop price does not guarantee the exit price

Hyperliquid stop orders activate when the trigger price is reached. The fill still depends on the order type, available liquidity and market movement. A market exit can fill past the trigger. A limit exit can remain unfilled. Enter a reserve that reflects both fees and possible slippage, then review the live order book before you send an order.

Hyperliquid accepts asset sizes at the asset-specific lot precision. The calculator does not know the selected asset, so the output is an upper bound. Round the size down to the permitted lot size. The result does not include funding, changes in collateral value, open-order exposure or liquidation mechanics.

Check costs, margin, execution and liquidation separately

Use the Hyperliquid fee calculator to build a larger reserve from fees and expected slippage. Read the order type guide before you choose a stop market or stop limit order. Compare account rules in the Hyperliquid margin guide.

After you set a size, use the liquidation calculator to stress an isolated position against maintenance margin. Review the risk and safety guide before you commit collateral. Each tool answers a different planning question.

Official sources and model boundary

The position-size formula is an independent planning method. Hyperliquid does not publish the formula as an order quote. The product facts on this page were reviewed against the official documentation on .

The calculator gives an estimate from the values you enter. It does not place an order, read your account or guarantee the loss at the stop.