The formula
Excel & Google Sheets (fill down)ExcelGoogle Sheets
=SUMIFS($C$2:$C$9,$A$2:$A$9,">="&E2,$A$2:$A$9,"<="&EOMONTH(E2,0))In F2 → 300
Excel 365 (one formula for all months)Excel
=SUMIFS(C2:C9,A2:A9,">="&E2:E5,A2:A9,"<="&EOMONTH(E2:E5,0))In G2, spills: [300], [850], [590], [60]
✓ Tested. All 5 Excel results in this example were recalculated in LibreOffice Calc 25.2 and matched the values shown.
Worked example
Paste the data below into a blank sheet starting at cell A1 (or download the cheat sheet, where every example is set up). Highlighted cells hold the formulas and show the expected results.
| A | B | C | D | E | F | G | |
|---|---|---|---|---|---|---|---|
| 1 | Date | Region | Amount | Month | |||
| 2 | Feb 27, 2026 | East | 300 | Feb 1, 2026 | 300 | 300 | |
| 3 | Mar 1, 2026 | West | 450 | Mar 1, 2026 | 850 | 850 | |
| 4 | Mar 9, 2026 | East | 120 | Apr 1, 2026 | 590 | 590 | |
| 5 | Mar 15, 2026 | East | 80 | May 1, 2026 | 60 | 60 | |
| 6 | Mar 31, 2026 | West | 200 | ||||
| 7 | Apr 1, 2026 | East | 500 | ||||
| 8 | Apr 18, 2026 | West | 90 | ||||
| 9 | May 2, 2026 | East | 60 |
How it works
- E2
- First day of the month (format it as "mmm yyyy").
- EOMONTH(E2,0)
- Last day of that month.
- $C$2:$C$9
- Locked ranges so you can fill the formula down.
Common errors and fixes
Month totals are 0?
The month cell is text like "March". Enter a real date (3/1/2026).
Totals include next month's first day?
Use "<"&EOMONTH(E2,0)+1 when dates contain times.
Does this work in Google Sheets?
The formulas tagged "Google Sheets" work as-is. Formulas tagged only "Excel" may need ARRAYFORMULA or a different function in Sheets.