Why monthly sessions and users’ data in Milestone Analytics may not exactly match with GA4?
Learn why GA4 and Milestone Analytics data does not match for monthly sessions and users
Why monthly sessions and users’ data in Milestone Analytics may not exactly match with GA4?
In GA4, the summation of daily data does not match with aggregated monthly data. This can be due to the following reasons:
- A session that spans midnight is considered a single session, though it is counted for both days.
- Sessions in GA 4 are based on estimations. Google uses algorithms such as HyperLogLog++ to optimize data processing for large volumes of data.
Milestone Analytics data is pulled for each day and added when displaying for a month.
It will match with the data summed for each day in GA4.
Milestone Analytics Sessions = Day 1+ Day 2 + Day 3………………+ Day 30
Should match with
GA 4 Sessions = Day 1+ Day 2 + Day 3………………+ Day 30
Please refer to the table with GA4 data for illustration.
| Day | Sessions | Total users |
| Aggregated Data | 27618 | 20353 |
| 1 | 2562 | 2210 |
| 2 | 2038 | 1769 |
| 3 | 2024 | 1721 |
| 4 | 1966 | 1672 |
| 5 | 1933 | 1627 |
| 6 | 1899 | 1671 |
| 7 | 1877 | 1618 |
| 8 | 1853 | 1562 |
| 9 | 1837 | 1543 |
| 10 | 1832 | 1567 |
| 11 | 1750 | 1485 |
| 12 | 1713 | 1434 |
| 13 | 1646 | 1430 |
| 14 | 1622 | 1360 |
| 15 | 1621 | 1380 |
| Total (Sum of daily data) | 28173 | 24049 |
Refer to the article from Google support on how sessions are calculated.