Convert days to years
Converting days to years is a common time task, whether you are checking a recipe, a spec sheet, a travel distance or a homework problem. Since 1 d equals 0.00273791 yr, the math is a single multiplication — and this page does it for you instantly, with the formula, a table of common values and answers to the questions people ask most.
Exact factor
How to convert days to years
To convert days to years, multiply the number of days by 0.00273791. For example, 10 d × 0.00273791 = 0.0273791 yr.
yr = d × 0.00273791
- Write down the value in days you want to convert.
- Multiply it by 0.00273791 (the exact d→yr factor).
- The result is your value in years. Check it below with the converter or the table.
Conversion table
Common values of days and their equivalents in years:
| d | yr |
|---|---|
| 1 | 0.00273791 |
| 2 | 0.00547581 |
| 3 | 0.00821372 |
| 4 | 0.0109516 |
| 5 | 0.0136895 |
| 10 | 0.0273791 |
| 20 | 0.0547581 |
| 25 | 0.0684477 |
| 50 | 0.136895 |
| 100 | 0.273791 |
| 250 | 0.684477 |
| 500 | 1.36895 |
About these units
Day (d). A day equals 24 hours or 86,400 seconds, approximating one rotation of the Earth. Calendars, deadlines and project plans are built on days.
Year (yr). A year is the period of Earth's orbit around the Sun. This tool uses the Gregorian average of 365.2425 days, which matches the calendar over the 400-year leap cycle.
Frequently asked questions
How do I convert days to years?
To convert days to years, multiply the number of days by 0.00273791. For example, 10 d × 0.00273791 = 0.0273791 yr. Or skip the math: type the value into the converter at the top of this page and the result updates instantly.
How many years are in 1 day?
1 d = 0.00273791 yr. That is the fixed relationship used by this converter and by international standards.
How many days are in 1 year?
1 yr = 365.243 d. If you are converting in the opposite direction, use our Year to Day converter for the dedicated table and FAQ.
Is the days to years conversion exact?
Yes. Both units are defined by international agreement, so the factor of 0.00273791 is exact. Displayed results are rounded to 6 significant digits only for readability.
What is day used for?
A day equals 24 hours or 86,400 seconds, approximating one rotation of the Earth. Calendars, deadlines and project plans are built on days.