Conversion Rate Formula: How to Calculate Conversion Rate
Summary
Conversion rate = Conversions ÷ Visits (or visitors) × 100. It is the share of sessions or users that completed a goal, such as a purchase or a demo request. A store with 1,949 purchases from 144,500 sessions converts at 1.35% per session. Always state whether the base is sessions or users.
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Conversion rate formula
Conversion rate % = Conversions ÷ Sessions × 100 (session-based) or Converting users ÷ Total users × 100 (user-based)- Conversions: Completed goal actions in the period: purchases, sign-ups or form submissions. GA4 calls the events you mark as goals key events.
- Sessions: Visits to the site or app. Use users instead when you want the share of people, not visits, that converted.
How to calculate conversion rate in Excel and Google Sheets
Excel, using the cells in the worked example below:
=SUM(C2:C4)/SUM(B2:B4)Worked example
An online furniture store pulls last quarter's sessions and purchases by device from GA4 to decide whether to prioritise a mobile checkout redesign.
| Device | Sessions | Purchases |
|---|---|---|
| Desktop | 41,800 | 794 |
| Mobile | 96,500 | 1,062 |
| Tablet | 6,200 | 93 |
- Total purchases = 794 + 1,062 + 93 = 1,949.
- Total sessions = 41,800 + 96,500 + 6,200 = 144,500.
- Site conversion rate = 1,949 ÷ 144,500 = 1.35%.
- By device (=C2/B2 filled down): desktop 1.90%, mobile 1.10%, tablet 1.50%.
- If mobile converted at the tablet rate of 1.50%, it would add about 96,500 × 0.004 = 386 purchases a quarter, which sizes the redesign opportunity.
Result: 1.35% session conversion rate
How to interpret conversion rate
Conversion rate depends heavily on what you sell and who arrives. Ecommerce stores commonly report session conversion rates in the low single digits, with high-ticket, considered purchases like furniture toward the lower end, while a demo-request page for warm visitors can convert far higher. The most useful comparisons are within your own site: by device, landing page, channel and new versus returning visitors. A drop in the blended rate can simply mean more low-intent traffic arrived, so check the mix before blaming the checkout.
Common mistakes
- Mixing bases. GA4 reports session key event rate and user key event rate; they can differ several-fold. Name the one you use.
- Reading the blended rate after a traffic mix change. A viral blog post can halve the site rate while every page converts as before.
- Counting multiple conversions per session as separate conversions when you want the share of sessions that converted at least once.
- Calling a difference real on small samples. 3 purchases vs 5 on a few hundred sessions is noise; wait for enough volume.
Calculate conversion rate with Better Analyst
Connect your data or upload a spreadsheet, then ask in plain English. Better Analyst writes and runs the calculation and shows the steps, so you can check the number.
- “Show session conversion rate by device and landing page for last quarter from GA4.”
- “Compare conversion rate for new versus returning users month by month.”
- “Which traffic channels have the biggest gap between sessions and purchases?”
Usually calculated from: Google Analytics, Google BigQuery, Google Sheets, MySQL, PostgreSQL.