Definition
Conversion rate is the percentage of visitors to your store who complete a desired action, most often a purchase. It is the headline efficiency metric of ecommerce: for a given amount of traffic, it tells you how effectively your store turns visits into revenue.
While purchase is the usual conversion, you can measure a conversion rate for any step: the rate at which product viewers add to cart, or checkout starters complete their order. Reading these step-level rates is how you find where the funnel leaks.
How to calculate conversion rate
The formula is:
Conversion rate = (Conversions ÷ Sessions) × 100
For example, a store with 800 orders from 40,000 sessions has a 2% conversion rate. Decide whether you measure against sessions or users and stay consistent, because the two give different numbers.
Rates vary widely by category, price point and traffic quality, so a commonly cited range of roughly 1% to 3% for ecommerce is a loose guide, not a target. The more useful benchmark is your own trend over time and the gap between your best and worst pages. You can price what a change in conversion is worth with the conversion rate lift calculator.
Why conversion rate matters for revenue
Conversion rate multiplies directly against your traffic, so improving it lifts revenue with no extra acquisition cost. That is why it sits at the centre of conversion rate optimization, and why a small improvement on a high-traffic store can be worth a great deal.
The trap is treating conversion rate as a single number to be nudged. A blended rate hides where the loss actually happens. A store can have an acceptable overall rate while its mobile checkout quietly fails, or while one high-traffic product page converts far below the rest. Reading conversion rate stage by stage, and by segment, is what turns it from a scoreboard into a map. Our guides to checkout optimization and product page optimization cover the two stages where conversion is most often won and lost.
From a Revenue Intelligence perspective, a low conversion rate at a specific step is a revenue leak: a located, fixable, priceable loss. The discipline is to find the step that is costing the most and fix it first, rather than chasing the overall percentage.
Related metrics
Your overall conversion rate is built from the step rates before it. The add-to-cart rate measures how well product pages turn viewers into cart additions, and the cart abandonment rate measures how many of those carts are then lost at checkout. Reading these two step metrics shows where a low overall conversion rate is actually being lost, and average order value then determines what each recovered conversion is worth.
In short
Conversion rate is conversions divided by sessions. It is the funnel's efficiency metric, it multiplies against traffic, and it is most useful read stage by stage rather than as a single blended number. Track your own trend, find the weakest step, and treat it as a priced leak to fix.