Free tool
Conversion rate calculator
The short answer
Conversion rate is conversions divided by visitors (or sessions), times 100: 96 enquiries from 4,200 visitors is 2.29%. With small numbers the true rate is uncertain, so this calculator also gives a 95% confidence interval, here roughly 1.9% to 2.8%, and the traffic you would need to hit a conversion target at today's rate.
On this page 7 sections
Conversion rate
Use the same unit every time you compare
For example, next month's lead goal
Conversion rate
2.29%
95% interval
1.88% to 2.78%
Visitors for target
6,563
Extra visitors needed
2,363
The interval is reasonably tight: the true rate is plausibly between 1.88% and 2.78%.
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The formulas
- Conversion rate = conversions / visitors x 100.
- 95% interval uses the Wilson score method. It stays sensible at low counts and never goes below 0% or above 100%, unlike the simple plus-or-minus formula.
- Visitors needed = target conversions / current conversion rate.
Worked example
A service business had 4,200 website visitors last month and 96 quote requests: 96 / 4,200 = 2.29%. The Wilson interval runs from about 1.88% to 2.78%, so a month at 2.0% or 2.6% would not, by itself, show anything changed. To reach 150 quote requests at 2.29% it would need about 6,563 visitors, roughly 2,360 more than it had.
Choosing the denominator
- Sessions or users. GA4 reports both session key event rate and user key event rate. Pick one and keep it; switching changes the number without changing the business.
- Exclude what cannot convert. Job seekers, existing customers logging in and your own team inflate the denominator. See excluding internal traffic in GA4.
- Count phone calls. For local businesses, many conversions are calls that never show up in GA4. A rate without calls understates paid search. See how to track phone calls from Google Ads.
- One conversion per goal. Decide whether a person who submits two forms counts once or twice, and keep it consistent.
Comparing two rates
The interval here describes one rate. To test whether version B really beats version A, use the A/B test significance calculator: it runs a two-proportion test on both. For tools that find where visitors drop off, see the best heatmap and CRO tools.
Questions
- How do you calculate conversion rate?
- Divide the number of conversions by the number of visitors or sessions and multiply by 100. 96 conversions from 4,200 visitors is 96 / 4,200 x 100 = 2.29%.
- Why show a confidence interval for a conversion rate?
- Because the measured rate is a sample. With 96 conversions from 4,200 visitors the true underlying rate is plausibly anywhere from about 1.9% to 2.8% at 95% confidence, so month-to-month changes inside that range are likely noise.
- Should conversion rate use sessions or users?
- Either works if you are consistent. Sessions suit sites where people convert on the visit; users suit longer decisions where people return several times before converting. GA4 reports both.
Sources
Related guides
How to track form submissions and leads back to their source
How to record the source, campaign and keyword of every form lead, in GA4 and in your CRM, and when a lead tracking platform is worth it.
A/B testing for small business: traffic and significance
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How to set up event tracking in GA4
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Heatmaps and session recordings explained
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