How do I convert years to days?

Multiply the year value by 365.25. So x yr × 365.25 = the equivalent in d.

How do I convert back from days to years?

Multiply the day value by 0.00273785. For example, 1 d = 0.00273785 yr.

Is the year bigger than the day?

Yes. 1 year is larger than 1 day — specifically 365.25 times larger.

Are these conversion factors exact?

Yes. The factor of 365.25 is derived directly from the SI definitions of year and day.

Years to Days Converter

1 yr = 365.25 d

1 year equals 365.25 days. To convert years to days, multiply the year value by 365.25. For quick reference: 1 yr = 365.25 d, 5 yr = 1826.25 d, 10 yr = 3652.5 d, 100 yr = 36525 d.

From

365.25

FormulaDays = Years × 365.25

Quick

How to convert years to days

Take your value
Start with your value in years.
Multiply by 365.25
Multiply the year value by 365.25. This is the exact conversion factor from years to days.
Read the result
The product is your value in days. For example, 5 yr × 365.25 = 1826.25 d.

Conversion formula

The exact factor from years to days is 365.25.

Days = Years × 365.25

Years to Days conversion table

Fifty common reference values, hand-picked for skim utility. Use the calculator above for any value not listed.

Conversion table from years to days
Years (yr)	Days (d)
1 yr	365.25 d
2 yr	730.5 d
3 yr	1095.8 d
4 yr	1461 d
5 yr	1826.3 d
6 yr	2191.5 d
7 yr	2556.8 d
8 yr	2922 d
9 yr	3287.3 d
10 yr	3652.5 d
15 yr	5478.8 d
20 yr	7305 d
25 yr	9131.3 d
30 yr	10958 d
45 yr	16436 d
60 yr	21915 d
90 yr	32873 d
100 yr	36525 d
120 yr	43830 d
150 yr	54788 d
180 yr	65745 d
240 yr	87660 d
300 yr	109575 d
360 yr	131490 d
450 yr	164363 d
500 yr	182625 d
600 yr	219150 d
750 yr	273938 d
900 yr	328725 d
1000 yr	365250 d
1200 yr	438300 d
1500 yr	547875 d
1800 yr	657450 d
2400 yr	876600 d
3000 yr	1095750 d
3600 yr	1314900 d
4500 yr	1643625 d
6000 yr	2191500 d
7200 yr	2629800 d
9000 yr	3287250 d
10000 yr	3652500 d
18000 yr	6574500 d
36000 yr	13149000 d
43200 yr	15778800 d
86400 yr	31557600 d
172800 yr	63115200 d
604800 yr	220903200 d
1000000 yr	365250000 d
31557600 yr	11526413400 d
100000000 yr	36525000000 d

Real-world reference

A common (non-leap) calendar year has 365 d. A leap year has 366 d. In days, that gives you: 1 yr = 365.25 d, 10 yr = 3652.5 d, 100 yr = 36525 d.

Frequently asked questions

How many days are in 1 year?: 1 year equals 365.25 days.
How do I convert years to days?: Multiply the year value by 365.25. So x yr × 365.25 = the equivalent in d.
What is 5 years in days?: 5 years equals 1826.25 days.
What is 10 years in days?: 10 years equals 3652.5 days.
What is 100 years in days?: 100 years equals 36525 days.
How do I convert back from days to years?: Multiply the day value by 0.00273785. For example, 1 d = 0.00273785 yr.
Is the year bigger than the day?: Yes. 1 year is larger than 1 day — specifically 365.25 times larger.
Are these conversion factors exact?: Yes. The factor of 365.25 is derived directly from the SI definitions of year and day.

About the year and the day

The year

Convertitive uses the Julian year, defined as exactly 365.25 days × 86,400 s/day = 31,557,600 seconds. This is the IAU-standard year used for astronomical distances such as the light year. The Gregorian (calendar) year averages 365.2425 days — about 11 minutes shorter — and the tropical year (one full seasonal cycle) is about 365.2422 days.

The day

The day (d) equals exactly 86,400 seconds, or 24 hours. This is the conventional 'civil' day used in calendars and contracts. The actual solar day (one full rotation of Earth relative to the Sun) varies slightly throughout the year; the difference is reconciled in atomic time scales using leap seconds.