Purchase conversion rate = (number of purchases ÷ total visitors) × 100. For example, 50 orders from 1,000 monthly visitors equals a 5.0% conversion rate, per Wall Street Prep's worked example.

It matters more than you'd think — the two denominators can differ by 20–30% on the same data, so pick one and stick with it. Kissmetrics notes some teams report conversions over sessions while others use unique visitors, and mixing definitions makes your trends meaningless.

Most ecommerce sites convert between 1–4% of visitors, with a global average around 2–3.65% depending on the source and year. Shopify stores average 1–3%, while the top 10% exceed 4.7%, according to LuckyOrange's 2025 benchmarks.

Mobile conversion rates consistently lag desktop by 1–2 percentage points — shoppers often browse on phones but check out on desktop. If your gap is larger than 1.5 points, LuckyOrange flags it as a sign of a specific mobile UX problem worth fixing.

Not necessarily. In Wall Street Prep's example, a company converting 2.00% and one converting 0.02% both generated identical $25,000 monthly revenue — the low-rate company just had far more traffic. Conversion rate is a diagnostic, not a revenue guarantee.

Measure over at least 30 days, ideally 90, segmented by traffic source and device — with only 200 conversions a month, a stage can show apparent 15% swings from noise alone. Benchmarks are directional, not targets: your own baseline and its trajectory matter most, as Kissmetrics explains.