How to calculate conversion rate
Conversion rate is the number of conversions divided by the number of chances to convert. Google Ads uses ad interactions as the denominator: 50 conversions from 1,000 interactions is 5%.[1] Microsoft Advertising divides by clicks.[2] On a website, the denominator is usually sessions or users, and a conversion is whatever you mark as a key event in analytics.[3]
- Conversion rate2.8%
- Visitors per sale35.7
- Cost per conversion$28.57
- Cost per visitor$0.80
A conversion is any action you define, from a purchase to a newsletter sign-up; textbooks call it the percentage of an audience completing a desired action.[5] Report each action separately rather than adding them together.
Traffic needed for a conversion goal
| Conversion rate | 50 conversions | 100 conversions | 500 conversions |
|---|---|---|---|
| 0.5% | 10,000 | 20,000 | 100,000 |
| 1% | 5,000 | 10,000 | 50,000 |
| 2% | 2,500 | 5,000 | 25,000 |
| 3% | 1,667 | 3,334 | 16,667 |
| 5% | 1,000 | 2,000 | 10,000 |
Multiply the visitors by your cost per click to get the budget, or let the ad spend calculator do the whole chain from goal to spend.
What a higher conversion rate is worth
A conversion-rate gain is worth the extra conversions it produces on traffic you already pay for. From 2% to 2.5% sounds small, but it is a 25% relative lift: 50 more orders per 10,000 visitors, at no extra media cost, which also cuts cost per acquisition by a fifth. Check the effect on CPA with the CPA calculator.
Before calling a lift real, make sure each version had enough traffic: on a few hundred visitors a handful of orders moves the rate by a full point. GA4’s engagement rate (engaged sessions ÷ sessions) helps diagnose why a page is not converting.[4]
Conversion rate mistakes
- Mixing users and sessions. One person can visit three times. Choose users or sessions and stick with it.
- Counting several conversions per visitor. If one visitor buys twice, conversions can exceed visitors; count one per visitor for a true rate.
- Comparing ad-platform and analytics rates. Platforms attribute conversions to ad interactions with their own windows; analytics uses sessions and its own attribution.
For a B2B pipeline where leads pass through several stages, the sales conversion rate page breaks the rate down stage by stage.
Frequently asked questions
How do you calculate conversion rate?
Conversions ÷ visitors (or clicks) × 100. 84 ÷ 3,000 = 2.8%.
How much traffic do I need for 100 sales?
100 ÷ conversion rate. At 2.5% you need 4,000 visitors.
What is a conversion in marketing?
Any action you count as a result: a purchase, a lead form, a sign-up or a call. Define it before measuring.
Is conversion rate based on clicks or sessions?
In ad platforms, ad interactions or clicks; in web analytics, sessions or users. Say which you used.