# How to add weeks to a date in Excel

Multiply the weeks by 7 and add them: `=B2+C2*7`.

**Excel:** `=B2+C2*7` (Every current version)

**Google Sheets:** the same formula works.

## Example

Sample data (row 1 is the header):

| A | B | C | D |
| --- | --- | --- | --- |
| Patient | Visit date | Follow-up in (weeks) | Follow-up date |
| P-301 | 2026-01-14 | 6 |  |
| P-302 | 2026-02-03 | 2 |  |
| P-303 | 2026-03-20 | 12 |  |
| P-304 | 2026-11-25 | 8 |  |
| P-305 | 2026-07-09 | 4 |  |

Formula in D2, filled to D6: `=B2+C2*7`

Result: 2/25/2026; 2/17/2026; 6/12/2026; 1/20/2027; 8/6/2026

## How it works

A week is 7 days, so multiplying the weeks by 7 and adding the result moves the date by whole weeks. The follow-up always falls on the same weekday as the visit.

## Other ways

- `=DATE(YEAR(B2),MONTH(B2),DAY(B2)+C2*7)`: The same date built from parts.
- `=WORKDAY(B2+C2*7-1,1)`: Moves a follow-up that would land on a weekend to the Monday after. Every visit here is on a weekday, so nothing moves. (Weekend follow-ups move to Monday.)

## Common mistakes

- Adding the weeks without multiplying, `=B2+C2`, adds days, not weeks.
- Format the result as a date; it can show as a serial number.

## Questions

**How do I subtract weeks?**

`=B2-C2*7`.

**How do I find how many weeks are between two dates?**

`=INT((end-start)/7)` gives the completed weeks.

Every formula and result on this page was checked by running it in the Spreadsheet Practice formula engine on 2026-10-30.

Source: https://spreadsheetpractice.com/formulas/add-weeks-to-a-date