For a Long: PNL = (Exit − Entry) × Quantity. For a Short: PNL = (Entry − Exit) × Quantity. The calculator subtracts open + close fees to give Net PNL, then divides by initial margin to show ROE %. ROE is the metric that captures leverage's amplification.

Isolated puts only the deposited margin at risk per position — easier to control max loss, easier to liquidate. Cross uses your entire account balance as collateral — more lenient liquidation price but a single bad trade can wipe out the whole account. Use isolated for directional bets, cross for hedging multiple positions against each other.

Long Liq = Entry × (1 − 1/Leverage + MMR). Short Liq = Entry × (1 + 1/Leverage − MMR). MMR is the maintenance margin rate (typically 0.5% on major exchanges). The calculator runs this automatically and shows the % move from entry that triggers liquidation.

Leverage multiplies your % return: a 1% price move with 10× leverage produces a 10% ROE on your margin. ROE measures return on the capital you actually posted, not on the notional position. This is the right metric for comparing leveraged trades to spot positions.

Yes — perpetual futures charge or pay a funding rate every 8 hours (varies by exchange) to keep the perpetual price tethered to spot. If you hold a Long when funding is positive, you PAY the rate; you receive it when funding is negative. Long-held positions can erode significantly via funding even without price movement.

There's no universal safe number, but most experienced traders use 2–10× on Bitcoin and Ethereum, lower on volatile altcoins. At 100× leverage a 0.5% adverse move triggers liquidation — and crypto routinely moves more than 0.5% per minute. Match leverage to the asset's volatility, not to the maximum the exchange offers.