E-commerce Profit and GST Margin Calculator

The calculator treats the entered selling price as GST-inclusive, estimates the GST component, then subtracts product cost, commission, fixed fee and shipping. Marketplace presets are planning defaults and can differ from your account or category.

The page starts with a GST-inclusive customer price, estimates the tax component as price × rate ÷ (100 + rate), and subtracts entered product, shipping, commission and fixed fees. For a ₹1,180 price at 18% GST, the implied GST component is ₹180 and the pre-tax value is ₹1,000.

Treat the output as contribution profit, not accounting profit. Reconcile commissions, TCS/TDS, refunds, promotions, payment fees, inventory write-offs and input-tax credit with the settlement and ledger for the same order period.

Use a consistent price basis before trusting any margin percentage. A price of ₹1,180 including 18% GST contains ₹180 of tax and ₹1,000 of pre-tax revenue when the tax is fully included in the displayed price. If product cost is ₹520, shipping ₹90, commission ₹100 and payment fee ₹25, contribution before overhead is ₹265. Dividing ₹265 by ₹1,000 gives a 26.5% pre-tax contribution margin; dividing by ₹1,180 gives 22.5% of customer cash. Both percentages can be mathematically correct, but they answer different questions. Label the denominator in reports. If your store displays tax-exclusive prices, enter that basis instead of removing tax a second time.

Worked order analysis should include realized, not advertised, revenue. Start with the amount actually retained after a discount, then subtract product cost, packaging, forward freight, marketplace commission, payment processing, advertising and expected return cost. For 100 orders at ₹1,000 pre-tax revenue, a 10% return rate does not necessarily mean 10% of product cost disappears: some items return to stock, some are damaged and some incur reverse freight. Model those outcomes separately. A monthly contribution margin can then be reconciled to settlement statements, while rent, salaries, software and owner drawings remain below contribution in the profit-and-loss account. This avoids calling a positive order contribution a guaranteed business profit.

Edge cases include tax-inclusive commissions, seller-funded coupons, free-shipping promises and mixed tax rates. A commission may be charged on the discounted item value or on the shipping amount. Input-tax credit can change the economic cost of eligible business purchases, but it should not be assumed without proper records. Refunds and chargebacks can reverse both revenue and fees. If a payment provider settles in another currency, use the settled exchange rate and conversion fee rather than a headline mid-market rate. The calculator cannot determine accounting treatment, income tax, TCS/TDS, VAT, GST registration or nexus obligations. Use an accountant and the official tax record for compliance.

Update notes and FAQs: retain a dated fee sheet, tax rate, channel and order sample. FAQ: Is a 30% margin good? It depends on repeat rate, overhead, working capital, return exposure and growth costs; no universal target exists. FAQ: Why is my settlement higher than modeled profit? Settlement is cash timing and may include tax, reserves or prior adjustments; it is not the same as contribution. FAQ: Can I compare two channels? Yes, if both scenarios include the same price basis, tax treatment, return reserve and advertising attribution. FAQ: Does the result include fixed overhead? Only if you enter it in a per-order field; allocate monthly overhead deliberately and avoid hiding it in shipping.