Gross Merchandise Value (GMV) is the headline metric used by every marketplace — from Amazon and Airbnb to the smallest SaaS-enabled platform — to express total transaction volume. Understanding GMV, and how it translates into platform revenue through a take rate, is essential for any founder, analyst or investor evaluating a marketplace business.
How it works
The core formula is deliberately simple:
GMV = Number of Orders × Average Order Value (AOV)
This gives the total value of all goods or services transacted on the platform during a period, before any deductions. The calculator lets you enter multiple periods or channels and aggregates them into a single total.
From total GMV, two further metrics matter:
Take-Rate Revenue = GMV × take rate (%)
Net Revenue = GMV × (1 − refund rate) × take rate (%)
The take rate is the commission or fee percentage kept by the platform on each transaction. The refund rate accounts for returns, chargebacks and cancellations — money that leaves the platform before the take rate is ever earned.
The calculator also derives the blended AOV (total GMV divided by total order count, not a simple average of the individual period AOVs), period-over-period GMV growth (comparing the first and last valid rows), and a per-row growth badge showing how each period compares with the previous one.
Worked example
A four-quarter marketplace year might look like this:
| Period | Orders | AOV | GMV |
|---|---|---|---|
| Q1 | 12,500 | £85 | £1.06M |
| Q2 | 14,200 | £88 | £1.25M |
| Q3 | 16,800 | £91 | £1.53M |
| Q4 | 21,000 | £97 | £2.04M |
| Total | 64,500 | £90.64 blended | £5.85M |
At a 15% take rate and 2% refund rate:
- Take-rate revenue: £5.85M × 15% = £877K
- Net revenue: £5.85M × (1 − 2%) × 15% = £859K
- Full-year GMV growth (Q1 → Q4): +93%
The bar and line chart overlays GMV (bars) against AOV (line) so you can see whether growth is coming from more orders, higher values, or both.
Formula note
GMV is a top-line volume metric, not a profitability metric. To reach actual profit you need to subtract payment processing fees (typically 1.5–2.9%), trust and fraud infrastructure, customer support, fulfilment costs (for physical goods), and all operating expenses. Many high-GMV marketplaces are cash-flow negative because their take rate does not cover unit economics. This calculator focuses on the GMV-to-net-revenue chain; pair it with a gross-profit or burn-rate calculator to close the full picture.
The blended AOV uses the correct revenue-weighted formula (total GMV ÷ total orders), not a naive average of period AOVs. This matters when period volumes differ — a holiday quarter with three times normal order volume would dominate the average if you naively averaged AOV figures.