Age in Weeks Calculator

Track age in weeks.

Calculate age in weeks instantly. Free weeks-old calculator for babies and milestones.

Calculator Inputs

About Age in Weeks

Track age in weeks.

Converts elapsed days to weeks + days.

Where it is used

Baby milestones, project age.

How to use the Age in Weeks

  1. Date of Birth — enter the value.
  2. Calculate — press the Calculate button to see the result instantly above.

Formula

floor(days/7) weeks + remainder days.

Examples

Example

dob:2026-01-01
Result: ≈ 36 weeks 2 days

Frequently Asked Questions

Why "weeks old"?
Common for newborns (< 1 year old).