In Python, load the data with pandas and compute revenue per customer from column totals for the whole period, or row by row for each month. On the sample data it returns 649.38.
Revenue per customer = Revenue ÷ Number of unique customers who ordered
What you need
Revenue per customer is how much revenue the average buying customer generated in a period: revenue divided by the number of distinct customers who placed an order. You need these columns, here from the sample file monthly.csv:
- df["revenue"]: revenue (net of discounts)
- df["buying_customers"]: customers who ordered
Step by step
- Install pandas (pip install pandas) and save monthly.csv next to your script.
- Run the script. The first print shows one row per month, the second the figure for the whole period.
- To use your own data, rename your columns to match, or change the names in the code.
The code
import pandas as pd
df = pd.read_csv("monthly.csv")
# Each month
df["revenue_per_customer"] = df["revenue"] / df["buying_customers"]
print(df[["month", "revenue_per_customer"]].round(2))
# Whole period: add up the parts first, then divide
revenue_per_customer_total = df["revenue"].sum() / df["buying_customers"].sum()
print(round(revenue_per_customer_total, 2))
What you should get
Run against the sample data, the code above returns these values:
| Month | revenue | buying_customers | revenue_per_customer |
|---|---|---|---|
| 2026-01 | 4,12,000 | 640 | ₹643.75 |
| 2026-02 | 4,38,500 | 681 | ₹643.91 |
| 2026-03 | 4,71,200 | 735 | ₹641.09 |
| 2026-04 | 4,55,800 | 702 | ₹649.29 |
| 2026-05 | 5,02,300 | 768 | ₹654.04 |
| 2026-06 | 5,48,900 | 830 | ₹661.33 |
| Whole period | 28,28,700 | 4,356 | ₹649.38 |
₹28,28,700 ÷ 4,356 = ₹649.38
Notes for Python
- Dividing by zero in pandas does not raise an error: it gives inf or NaN. Check with df.replace([float("inf"), -float("inf")], float("nan")) before averaging or plotting.
- For the whole period, sum the columns first and then divide. df[col].mean() of the monthly results weights a small month the same as a large one.
- pct_change(), groupby() and resample() extend the same idea to weekly data, product categories and daily rows.
Where revenue per customer misleads
- Only customers who ordered are in the denominator. Dividing by your whole customer list answers a different question (revenue per account, including inactive ones).
- For subscription revenue, ARPU (average revenue per user, from MRR) is the more usual measure.
- As with every average, a few very large customers can carry it. Look at the spread as well.
The full explanation, with a calculator, is on the Revenue per customer page.
Same metric, other tools
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- 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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