Convert years to seconds

1 yr=31,557,600s

Use the converter below to change any years value into seconds instantly — with formula, conversion table, and real-world examples.

You have

Equals

31,557,600

Conversion formula

Forward

seconds = years × 31,557,600

Reverse

years = seconds × 3.1688e-8

Example: 10 yr × 31,557,600 = 315,576,000 s.

About both units

From

Year

The Julian year equals 365.25 days — the time for Earth to complete one orbit around the Sun. The Gregorian civil year averages 365.2425 days thanks to the leap-year rule. Most unit conversion uses the Julian value.

Real-world: Human average lifespan: 73 years (global). EU adult age: 18 years. Typical mortgage: 25–30 years.

Read full year reference →

Second

The second is the SI base unit of time. It is defined by the caesium-133 atomic transition: 9,192,631,770 cycles of this oscillation equal one second. Modern atomic clocks maintain the second to about 10⁻¹⁶ accuracy — you would lose one second in 100 million years.

Real-world: A blink takes 100–400 ms. Heartbeat at rest ~1 s. The 100 m sprint world record is 9.58 s (Usain Bolt).

Read full second reference →

Year to Second conversion table

Common years to seconds values for quick reference.

Year (yr)	Second (s)
1 yr	31,557,600 s
5 yr	157,788,000 s
10 yr	315,576,000 s
30 yr	946,728,000 s
60 yr	1,893,456,000 s
120 yr	3,786,912,000 s
300 yr	9,467,280,000 s
600 yr	18,934,560,000 s
1,800 yr	56,803,680,000 s
3,600 yr	113,607,360,000 s

Tips & common mistakes

Quick tips

Julian year = 365.25 days = 31,557,600 seconds.
Gregorian civil year averages 365.2425 days (97 leap days in 400 years).
Astronomical "year" can be tropical (365.2422 d), Julian (365.25 d) or sidereal (365.2564 d).

Avoid these

Using 360 days/year (financial convention) in scientific calculations.
Confusing Julian and tropical years in precise astronomy.
Mixing fiscal year (varies by country) with calendar year.

Frequently asked questions

How many seconds in a year?

One year equals 31,557,600 seconds.

How do I convert years to seconds?

Multiply the year value by 31,557,600 to get the equivalent in seconds.

What is 100 years in seconds?

100 years equals 3,155,760,000 seconds.

Is a year bigger than a second?

Yes. 1 year equals 31,557,600 seconds, so one year is larger.

How to convert years to seconds without a calculator?

Multiply by 31,557,600 for a quick estimate; use a calculator for precise results.

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