# Conversion Rate Formula: How to Calculate Conversion Rate

- URL: https://betteranalyst.com/metrics/conversion-rate
- Published: 2026-10-30
- Updated: 2026-10-30
- Author: David Bressler, Founder (https://betteranalyst.com/authors/david-bressler)

> **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.

Category: [Ecommerce](https://betteranalyst.com/metrics#ecommerce)

Conversion rate formula with a GA4 device example, the Excel formula, session vs user conversion rate in GA4, and the segment-mix trap.

## 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.

*Sessions and purchases by device, last quarter (table starts in cell A1)*

| Device | Sessions | Purchases |
| --- | --- | --- |
| Desktop | 41,800 | 794 |
| Mobile | 96,500 | 1,062 |
| Tablet | 6,200 | 93 |

1. Total purchases = 794 + 1,062 + 93 = 1,949.
2. Total sessions = 41,800 + 96,500 + 6,200 = 144,500.
3. Site conversion rate = 1,949 ÷ 144,500 = 1.35%.
4. By device (=C2/B2 filled down): desktop 1.90%, mobile 1.10%, tablet 1.50%.
5. 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](https://betteranalyst.com/data-connectors/google-analytics), [Google BigQuery](https://betteranalyst.com/data-connectors/bigquery), [Google Sheets](https://betteranalyst.com/data-connectors/google-sheets), [MySQL](https://betteranalyst.com/data-connectors/mysql), [PostgreSQL](https://betteranalyst.com/data-connectors/postgresql).

[Try Better Analyst free](https://betteranalyst.com/signup)

## Further reading

- [Connect Google Analytics 4](https://betteranalyst.com/data-connectors/google-analytics)
- [CTR formula](https://betteranalyst.com/metrics/click-through-rate)
- [COUNTIFS function](https://betteranalyst.com/excel/countifs-function)
- [Better Analyst for marketing teams](https://betteranalyst.com/solutions/marketing-teams)
- [Web dashboards](https://betteranalyst.com/product/dashboards)

## Frequently asked questions

### How does GA4 calculate conversion rate?

GA4 renamed conversions to key events. Session key event rate is the share of sessions with at least one key event; user key event rate is the share of users who triggered one. In the GA4 Data API they are sessionKeyEventRate and userKeyEventRate.

### How do I calculate conversion rate in Excel?

Divide conversions by sessions: =C2/B2 for one row, =SUM(C2:C4)/SUM(B2:B4) for the total, then format as a percentage with two decimals.

### Should I use sessions or users for conversion rate?

Use sessions to judge site experience per visit, and users for the share of people who eventually convert. For long buying cycles, user-based rates are usually more meaningful.

## Related metrics

- [Click-Through Rate Formula: How to Calculate CTR (Excel)](https://betteranalyst.com/metrics/click-through-rate)