Years to Days Converter

About the yr to d calculation

One year is exactly 365.243 days, so converting between them is a single multiplication. Enter any value above and the result updates as you type. The mean Gregorian year — 365.2425 days, which is why leap years exist. Twenty-four hours, or 86,400 seconds — one full rotation of the Earth relative to the Sun.

Formula

d = yr × 365.243

1 yr = 365.243 d
1 d = 0.00273791 yr

Worked example

To convert 1 yr, multiply by 365.243: 1 × 365.243 = 365.243 d.

Frequently asked questions

How many days are in a year?

There are 365.243 days in one year. To convert any amount, multiply the number of years by 365.243.

How do I convert days back to years?

Divide instead of multiplying, or equivalently multiply by 0.00273791. One day is 0.00273791 years.

Is this conversion exact?

For seconds through weeks, yes — they are fixed multiples. The year is the mean Gregorian year of 365.2425 days, which is an average rather than the length of any particular calendar year.

Where is each of these units used?

Years: the mean Gregorian year — 365.2425 days, which is why leap years exist. Days: twenty-four hours, or 86,400 seconds — one full rotation of the Earth relative to the Sun.

Sources

• NIST Special Publication 811 — Guide for the Use of the International System of Units