In Excel or Google Sheets, contribution margin for a whole period is (SUM(B2:B7) - SUM(C2:C7) - SUM(F2:F7) - SUM(G2:G7)) / SUM(B2:B7), where each SUM covers one column of monthly figures. On the sample data it returns 10.01%.
Contribution margin = (Revenue − COGS − Shipping − Marketing) ÷ Revenue × 100
What you need
Contribution margin is the share of revenue left after the costs that grow with each sale: cost of goods, shipping and, for online brands, marketing. You need these columns, here from the sample file monthly.csv:
- Revenue (net of discounts): column B (revenue)
- Cost of goods sold: column C (cogs)
- Shipping cost: column F (shipping_cost)
- Marketing spend: column G (marketing_spend)
Step by step
- Download monthly.csv below and open it: in Excel use File → Open; in Google Sheets use File → Import → Upload. The headers land in row 1 and the six months in rows 2 to 7.
- Click any empty cell and enter =(SUM(B2:B7) - SUM(C2:C7) - SUM(F2:F7) - SUM(G2:G7)) / SUM(B2:B7) for the whole six months. It adds up each column first and then does the arithmetic once, which is the correct way to combine months.
- For each month, click AQ2, enter =(B2 - C2 - F2 - G2) / B2 and drag the fill handle down to row 7.
- Format the results as a percentage (Home → %, or Format → Number → Percent in Sheets). The formula returns a fraction such as 0.45, which the format shows as 45%.
- If a month can have zero in the denominator, wrap the formula so it shows a blank instead of #DIV/0!: =IFERROR((B2 - C2 - F2 - G2) / B2,"").
The formulas
=(SUM(B2:B7) - SUM(C2:C7) - SUM(F2:F7) - SUM(G2:G7)) / SUM(B2:B7)=(B2 - C2 - F2 - G2) / B2What you should get
Run against the sample data, the code above returns these values:
| Month | revenue | cogs | shipping_cost | marketing_spend | contribution_margin |
|---|---|---|---|---|---|
| 2026-01 | 4,12,000 | 2,26,600 | 49,100 | 96,000 | 9.78% |
| 2026-02 | 4,38,500 | 2,36,800 | 52,400 | 1,02,000 | 10.79% |
| 2026-03 | 4,71,200 | 2,59,200 | 56,800 | 1,18,000 | 7.89% |
| 2026-04 | 4,55,800 | 2,55,200 | 54,000 | 99,000 | 10.44% |
| 2026-05 | 5,02,300 | 2,71,200 | 59,200 | 1,24,000 | 9.54% |
| 2026-06 | 5,48,900 | 2,90,900 | 64,200 | 1,31,000 | 11.44% |
| Whole period | 28,28,700 | 15,39,900 | 3,35,700 | 6,70,000 | 10.01% |
(₹28,28,700 − ₹15,39,900 − ₹3,35,700 − ₹6,70,000) ÷ ₹28,28,700 × 100 = 10.01%
Notes for Excel
- Google Sheets accepts the same formulas. If your spreadsheet locale uses a comma as the decimal separator, Sheets and Excel expect semicolons between function arguments instead of commas.
- Averaging the monthly results with AVERAGE() gives a different and usually wrong answer for the period, because every month counts the same however large it was.
- Excel tables (Insert → Table) let you write the same formula with column names instead of letters, which is easier to read and survives inserted columns.
Where contribution margin misleads
- Definitions vary. Some include payment fees and packaging, some exclude marketing (often called CM1, CM2, CM3). State which costs you subtract.
- Marketing spent this month brings customers who buy next month too, so monthly contribution margin swings with campaign timing.
- Returns and undelivered COD orders carry shipping both ways. Include return shipping if it is material.
The full explanation, with a calculator, is on the Contribution margin page.
Same metric, other tools
Related metrics in Excel and Google Sheets
Learn more about Excel
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.
Legal entity
Devansh Yadav
Moradabad, Uttar Pradesh
Governing law: Courts at Moradabad, Uttar Pradesh
Phone: +91 8433475698
Legal: legal@analyzeit.in