In SQL, net revenue retention for the whole period is ROUND(100.0 * (SUM(mrr_start) + SUM(mrr_expansion) - SUM(mrr_contraction) - SUM(mrr_churned)) / SUM(mrr_start), 2) over the monthly table. On the sample data it returns 96.18.
NRR = (MRR at start + Expansion − Contraction − Churned) ÷ MRR at start × 100
What you need
Net revenue retention (NRR), or net dollar retention, is the share of recurring revenue you keep from existing customers after upgrades, downgrades and cancellations, as a percentage of what they paid at the start. You need these columns, here from the sample file monthly.csv:
- mrr_start: MRR at start of month
- mrr_expansion: expansion MRR
- mrr_contraction: contraction MRR
- mrr_churned: churned MRR
CREATE TABLE monthly (
month TEXT, -- 'YYYY-MM'
mrr_start INTEGER,
mrr_expansion INTEGER,
mrr_contraction INTEGER,
mrr_churned INTEGER
);Step by step
- Load monthly.csv into a table called monthly. The table only needs the month column and the columns below.
- Run the first query to get one row per month.
- Run the whole-period query. It adds up each column first and divides once; averaging the monthly results gives a different, usually wrong, answer.
The queries
SELECT
month,
ROUND(100.0 * (mrr_start + mrr_expansion - mrr_contraction - mrr_churned) / NULLIF(mrr_start, 0), 2) AS nrr
FROM monthly
ORDER BY month;SELECT ROUND(100.0 * (SUM(mrr_start) + SUM(mrr_expansion) - SUM(mrr_contraction) - SUM(mrr_churned)) / NULLIF(SUM(mrr_start), 0), 2) AS nrr
FROM monthly;What you should get
Run against the sample data, the code above returns these values (in percent):
| Month | mrr_start | mrr_expansion | mrr_contraction | mrr_churned | nrr |
|---|---|---|---|---|---|
| 2026-01 | 1,80,000 | 6,000 | 3,500 | 9,000 | 96.39% |
| 2026-02 | 1,95,500 | 7,200 | 4,100 | 10,200 | 96.37% |
| 2026-03 | 2,12,900 | 6,800 | 3,900 | 11,800 | 95.82% |
| 2026-04 | 2,30,000 | 7,400 | 4,600 | 12,900 | 95.61% |
| 2026-05 | 2,41,400 | 8,100 | 4,200 | 12,100 | 96.60% |
| 2026-06 | 2,60,400 | 8,600 | 4,800 | 13,400 | 96.31% |
| Whole period | 13,20,200 | 44,100 | 25,100 | 69,400 | 96.18% |
(₹13,20,200 + ₹44,100 − ₹25,100 − ₹69,400) ÷ ₹13,20,200 × 100 = 96.18%
Notes for SQL
- Integer columns divide as integers in PostgreSQL, SQLite and SQL Server, so 3 / 4 gives 0. Multiplying by 1.0 (or 100.0) first makes the division decimal.
- NULLIF(x, 0) turns a zero denominator into NULL, so the query returns NULL for that row instead of failing with a division-by-zero error.
- Tested on SQLite and DuckDB. SUM, NULLIF and ROUND work the same in PostgreSQL, MySQL and BigQuery; SQL Server uses TOP instead of LIMIT where a query has one.
Where net revenue retention misleads
- Do not include new customers' revenue; NRR is about the customers you already had.
- A price rise lifts NRR once, without customers valuing the product more.
- Monthly NRR to the twelfth power approximates yearly NRR only if the rate is steady.
The full explanation, with a calculator, is on the Net revenue retention (NRR) page.
Same metric, other tools
Related metrics in SQL
Learn more about SQL
- Python and SQL for data analysis, side by side — 3 min read
- How to find out what changed in your sales data — 2 min read
About the data on this page
The figures come from a small made-up dataset, printed above in full so you can check every number by hand. Download it as monthly.csv. The results are computed from those rows when the page is built, and the Excel formulas, SQL and Python on these pages are run against the same rows before publishing, so the code and the answers agree.
To get these numbers from your own data without writing formulas, try AnalyzeIt: ask in plain words and it shows the working behind every figure.
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