Free tool · website, ecommerce and ad conversion rates
Free conversion rate calculator
Conversion rate is the share of visits that end in a conversion, such as a sale, sign-up or enquiry: conversions divided by visits, multiplied by 100. This free conversion rate calculator works it out for a website, an online shop or an ad campaign, and adds revenue per visit and per conversion when you enter revenue.
By the Dolphin Analytics team · Last updated · Formula as defined in Google Ads Help (conversion rate)
200 ÷ 8,000 × 100 = 2.50% - Revenue per session
- £1.50
- Revenue per conversion
- £60.00
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What is a conversion rate?
A conversion rate is the percentage of visits or clicks that end in the action you want: a purchase, a form fill or a booked call. Online shops count orders against sessions, lead generation sites count enquiries, and ad platforms count conversions against ad clicks or interactions.
How do you calculate conversion rate?
Divide conversions by visits and multiply by 100. Google Ads Help uses the same formula, with ad interactions in place of visits.
| Measuring | Formula | Worked example |
|---|---|---|
| Website | conversions ÷ sessions × 100 | 200 ÷ 8,000 × 100 = 2.50% |
| Online shop | orders ÷ sessions × 100 | 200 ÷ 8,000 × 100 = 2.50% |
| Ad campaign | conversions ÷ ad interactions × 100 | 50 ÷ 1,000 × 100 = 5.00% |
Why does GA4 show a different conversion rate?
GA4 calls conversions key events and reports rates per session or per user: the share of sessions, or of users, with at least one key event. A session with two orders counts once in GA4's session rate but twice in an orders ÷ sessions sum, so the two figures drift apart on sites where people buy more than once per visit.
Frequently asked questions
Is this conversion rate calculator free?
Yes. The Dolphin Analytics conversion rate calculator is free, needs no sign-up and runs in your browser, so the numbers you enter never leave your device.
What is a good conversion rate?
No single conversion rate is good for every site. It changes with industry, price, traffic source and device, so the most useful comparison is against your own past months.
Should I use sessions or users?
Use sessions for most website and shop reporting, because one person can visit several times before buying. Use users when you want the share of people who ever converted. Stick to one so the trend stays comparable.
Why is my Google Ads conversion rate higher than GA4's?
They measure different things. Google Ads divides conversions by ad interactions and credits them to the ad click; GA4 divides by all sessions from every channel and uses its own attribution. Compare each with itself over time.
Does a higher conversion rate always mean more revenue?
No. A discount can lift conversion rate while cutting order value. Add revenue above to see revenue per visit, which captures both.
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