Conversion Rate Calculator
Find the share of visitors who complete a goal, with a confidence range.
About the Conversion Rate Calculator
Enter the number of visitors (or sessions) and how many converted: bought, signed up or completed whatever goal you track. Add the average order value to see revenue per visitor.
Small samples give noisy rates, so the result includes a 95% confidence interval: the range the true rate very likely lies in. Typical e-commerce conversion rates are 1–4%.
The formula
Rate = conversions ÷ visitors; 95% CI = p ± 1.96 √(p(1 − p) ÷ n)
- p
- conversion rate as a decimal
- n
- number of visitors
Worked example
12,000 visitors and 300 orders, average order 60
- Rate = 300 ÷ 12,000 = 2.5%
- 95% confidence interval: 2.22% to 2.78%
- Revenue per visitor: 2.5% × 60 = 1.50
Things to keep in mind
- The interval uses a normal approximation, which is poor with very few conversions (under about 10).
Questions people ask
Sessions or users?
Either, but be consistent when comparing periods.
How do I compare two pages?
Use the A/B test (two-proportion) significance calculator.
How many visitors do I need?
More than most people expect: to see a change from 2.5% to 3% reliably takes tens of thousands of visitors per version.