Market Design
Marketplace Take-Rate Designer
What a platform can safely tax. A take rate is not a price — it is a tax on transactions someone else could, in principle, do without you, and its ceiling is set by the seller's alternative rather than by your costs or your ambitions. This puts the two numbers that actually bind side by side: the rate above which a rational seller starts going direct, and the rate that maximises your revenue this quarter. They are not the same number, and the gap between them is where most platform self-harm happens.
Inputs
- Monthly GMV
- Current take rate
- Seller's margin before your fee
- What going direct costs a seller
- Switching friction
- GMV lost per extra point of take
How to use this calculator
- Enter monthly GMV (the value of transactions crossing the platform, not your revenue from them) and the take rate you charge today, all-in. If sellers also pay for placement, advertising, or payments, fold those in: the seller compares one total against one alternative, and so should you.
- Work out what going direct genuinely costs a seller, as a share of their sales. Paid acquisition to replace your demand, payments, fulfilment, support, and whatever software they would have to buy. This is the number that sets your ceiling, and the number platform teams most consistently guess high.
- Set switching friction honestly. It is the extra take a seller tolerates because of the reviews, ranking, and working capital they would forfeit. Real, but it decays every year, and it collapses the moment a rival publishes a migration path.
- Read the headline: the take rate at which a clear-eyed seller stops preferring you. Then read the headroom row. Headroom is the asset; the take rate is just how fast you spend it.
- Compare the revenue-maximising rate with your current one, and treat the gap as a warning rather than an opportunity. That number is computed on the sellers you already have, and it is blind to the sellers who now never join.
- Run it again with switching friction set to zero. That is the same platform in three years, after the migration tooling exists. If the business only works with the friction in, you are charging for lock-in rather than for value.
What each term means
- Take rate
- The share of transaction value the platform keeps: commission plus every other fee the seller pays to trade on it. All-in is the only version worth modelling, because it is the only version the seller experiences.
- GMV
- Gross merchandise value: everything transacted across the platform before your cut. It is a volume measure, not revenue, and confusing the two is how take-rate arguments go wrong.
- Indifference rate
- The take at which the seller is exactly as well off with you as going direct. Above it you are being paid by inertia; below it you are being paid for value.
- Switching friction
- Everything that makes leaving cost more than the arithmetic says: ratings, ranking history, working capital, staff habit. Genuine, and a depreciating asset.
- Disintermediation
- Both sides meeting on the platform and then transacting off it. The characteristic failure of a rate set too high, and it appears as flat GMV rather than as churn.
- Revenue-maximising rate
- The single-period peak of rate × retained volume. Almost never the right rate, because the model that produces it cannot see the supply that stops arriving.
- Lerner index
- Margin as a share of price, which equals the inverse of demand elasticity. The same logic behind a take rate: what you can charge is set by the alternative, not by your costs.
Educational disclaimer: Outputs are simplified educational estimates built from the numbers you enter — they are not financial, legal, tax, or investment advice, and real decisions deserve verified figures and qualified professionals.