Methodology

Every number on the calculator comes from the contract rules below and the formulas on this page. All maths runs in exact decimals in your browser; nothing is sent anywhere. Rules last checked 2026-10-15.

Formulas

For entry E, stop S, contract size c (coin per lot), fee rates r (maker or taker per leg), GST g and the INR rate fx:

budgetUSD  = budgetINR / fx
perLotLoss = |E − S| × c + (E × r_entry + S × r_stop) × c × (1 + g)
lots       = floor(budgetUSD / perLotLoss)
lossUSD    = lots × perLotLoss
notional   = lots × c × E          (one leg)
margin     = notional / leverage
breakeven  = E × (1 ± r_entry(1+g)) / (1 ∓ r_taker(1+g))   (long / short, taker exit)

The “without fees” comparison uses floor(budgetUSD / (|E − S| × c)) and then charges the real fees on that size. The leverage warning approximates isolated liquidation at an adverse move of 1/leverage − maintenance margin − isolated liquidation fee; it is an estimate, not Delta's liquidation price. Display rounding is half-up to 2 decimals; intermediate values are not rounded.

Contract rules

The flat-margin limit is Delta's API field max_leverage_notional; Delta's help article on isolated margin does not publish the threshold as a number, so the calculator refuses sizes above it rather than guess the margin.

Sources

• product fields — checked 2026-10-15
• max leverage per contract (BTC/ETH 200x; SOL 100x) — checked 2026-10-15
• isolated margin: flat below Position Threshold, linear above; isolated liquidation fee rates — checked 2026-10-15
• USD-INR fixed rate 85 — checked 2026-10-15
• GST on trading fees — checked 2026-10-15
• fee rates, 18% GST, calculator behaviour (official benchmark) — checked 2026-10-15
• Trade Size = margin x leverage / (entry x 0.001) — checked 2026-10-15
• previous product snapshot — checked 2026-10-15
• ETHUSD product fields — checked 2026-10-15
• SOLUSD product fields — checked 2026-10-15

Delta's in-app Trade Size calculator works from margin × leverage (per Delta's help article as of 2026-10-15); if Delta adds stop-loss sizing, tell us and we will review this page.

Checked against Delta's fee calculator

We entered the same trades into Delta's fee calculator (logged out) and compared. Delta's page truncates decimals, so differences up to $0.01 are expected. Its calculator treats every trade as long, shows entry + exit notional combined, and has the Scalper Offer (no closing fee) switched on by default — rows marked ′ have it switched off.

Stop-loss sizing checks

For each case we sized the trade, then entered our lot count, one lot more and the no-fee lot count into Delta's calculator with the stop as the exit price. Our size always stays within the budget; one more lot always goes over.

Not included

• Funding payments, slippage and the settlement fee.
• Scalper Offer, VIP or promotional fee discounts.
• Delta's exact liquidation price, cross margin and portfolio margin.
• Positions above the flat-margin notional limit.