Conversion rate
Also: CVR, CR, Conversion ratio, Taux de conversion
The percentage of visitors or prospects who complete a desired action (purchase, sign-up, contact form), calculated as conversions divided by total opportunities.
What it is
Conversion rate is the share of people who complete a defined target action out of everyone who had the opportunity to do so. It is expressed as a percentage:
Conversion rate = (Conversions / Total opportunities) x 100
A "conversion" is any action you decide to measure: a purchase, a sign-up, a demo request, a filled contact form, a file download, or a subscription. "Total opportunities" is usually visitors, sessions, or qualified leads, depending on what you are measuring.
Why it matters
Conversion rate turns raw traffic into a measure of effectiveness. Two campaigns can bring the same number of visitors, but the one with a higher conversion rate produces more results from the same volume. It is central because:
- It links activity (traffic, reach) to outcomes (revenue, leads).
- It is a lever you can improve without buying more traffic.
- It exposes friction in a funnel, page, or process.
How it is used in practice
- Define the action precisely. "Sign-up" and "paid subscription" are different conversions with different rates.
- Match numerator and denominator. If you count purchases, the base should be sessions or users who could purchase, not raw pageviews.
- Segment. Overall rate hides differences by channel, device, geography, or audience.
- Compare against a baseline. A rate is only meaningful against history, a target, or a control group (A/B test).
- Watch the funnel. A single conversion rate often decomposes into step rates (visit to cart, cart to checkout, checkout to paid).
Worked example
An e-commerce site gets 50,000 sessions in a month and records 1,500 orders.
- Conversion rate = 1,500 / 50,000 = 3.0%
Suppose average order value is 80 EUR. Monthly revenue is 1,500 x 80 = 120,000 EUR.
Now the team runs an A/B test on the checkout page and lifts the rate to 3.6% with the same traffic:
- New orders = 50,000 x 3.6% = 1,800
- New revenue = 1,800 x 80 = 144,000 EUR
That is 24,000 EUR extra per month with no additional ad spend, purely from a 0.6 point improvement.
Common pitfalls
- Comparing rates across mismatched denominators.
- Ignoring statistical significance in tests with small samples.
- Optimizing conversion rate while quietly lowering value per conversion.