Conversion Rate Calculator
Work out a conversion rate and how sure you can be of it: a confidence interval, the traffic needed to pin it down, and the conversions needed for a target. Then follow a funnel step by step, or compare channels and segments on one chart.
Enter visitors and conversions.
What this conversion rate calculator does differently
A conversion rate is conversions divided by visitors, and every calculator gets that right. What they leave out is how much to trust it. Twelve sales from 400 visitors and 300 from 10,000 are both 3%, but the first could easily come from a page that really converts at 1.7% or 5%. This calculator gives the range with the rate, and says how much more traffic would narrow it.
| gigacalculator | LanderLab | This tool | |
|---|---|---|---|
| Conversion rate | Yes | Yes | Yes |
| How sure the rate is | No | No | Interval at 90, 95 or 99% |
| Traffic needed for a precise rate | No | No | Yes |
| Target rate | No | Traffic needed for a target | Conversions needed, and whether you may already be there |
| Revenue per visitor | No | Yes | Yes, with its range |
| Funnel, step by step | No | No | Up to 12 steps, biggest drop flagged |
| Compare segments or channels | No | No | Up to 40, with an interval chart |
| Export | Embed code | Result link | CSV, Markdown, share link |
Pages as fetched on 2 November 2026. Some sites block automated fetches and are not compared.
How to calculate conversion rate
Divide the number of conversions by the number of visitors who could have converted, and multiply by 100. 132 sign-ups from 4,800 visitors is 132 / 4,800 = 2.75%. The hard part is the denominator: sessions, users, landing page visitors and qualified leads all give different rates for the same site, so two rates are only comparable if they count the same thing. The conversion rate benchmarks post covers why published benchmarks disagree for that reason.
How sure is the rate? Confidence intervals
A rate measured from a sample of visitors is an estimate. The interval is the range of underlying rates that could reasonably have produced what you saw. The calculator uses the Wilson score interval, which the NIST/SEMATECH Engineering Statistics Handbook describes and which stays sensible with small counts and rates near 0%, where the simpler textbook formula can give impossible ranges below zero.
The interval narrows with the square root of the traffic, so halving the margin takes about four times the visitors. The table of visitors needed shows that cost for your current rate. When there are fewer than 10 conversions, the calculator warns that the rate is only a rough guide.
Funnel conversion rates
A funnel shows where people stop. For each step the calculator gives the rate from the step before and from the first step, with an interval on each step rate, and flags the step with the lowest rate as the biggest drop. Every step needs to count the same unit over the same dates: if one step counts sessions and the next counts users, a step can appear to gain people, and the calculator warns when that happens.
Comparing segments and channels
Paste a line per channel, device, landing page or month. The chart shows each segment’s rate with its interval against the overall rate. A segment is marked above or below only when its whole interval is on one side; a small channel with a high rate but a wide interval is marked “cannot tell”, which is often the honest answer. This is a guide rather than a formal test. To test two versions against each other, use the A/B test significance calculator.
How to use this calculator
- Choose a modeOne rate, a funnel, or a list of segments.
- Enter the countsVisitors and conversions, funnel steps, or one line per segment.
- Pick a confidence level95% is the usual choice; 90% gives a narrower range, 99% a wider one.
- Add a target or revenueOptional: see the conversions needed and revenue per visitor.
- Read the rangeThe rate, its interval, and the traffic needed to narrow it.
- ExportCSV, a Markdown summary or a share link.