How many seconds in a day?

There are 86,400 seconds in a day (24 × 60 × 60).

Why is a month shown as an average?

Calendar months range from 28 to 31 days. For unit conversion we use the average Gregorian month — 30.437 days (2,629,746 seconds) — which is one twelfth of an average year.

How many milliseconds in a second?

Exactly 1,000. Programmers often work in milliseconds (and nanoseconds for high-precision timing), which is why those units are included.

Time Converter

Convert time durations — seconds, minutes, hours, days, weeks, months, and years, plus milliseconds and nanoseconds for programming.

Converters

Nanosecond ns

Microsecond µs

Millisecond ms

Second s

Minute min

Hour h

Day d

Week wk

Month (avg) mo

Year (avg) yr

About the time converter

This converts durations (how long something lasts), not clock times. Months and years are averages — a month is 1/12 of an average Gregorian year, and a year is 365.2425 days — so use them as estimates, not calendar-exact values.

Conversion reference

1 s	=	1.0000000e+9 ns	Nanosecond
1 s	=	1000000 µs	Microsecond
1 s	=	1000 ms	Millisecond
1 s	=	1 s	Second
1 s	=	0.016666667 min	Minute
1 s	=	0.00027777778 h	Hour
1 s	=	1.1574e-5 d	Day
1 s	=	1.6534e-6 wk	Week
1 s	=	3.8026e-7 mo	Month (avg)
1 s	=	3.1689e-8 yr	Year (avg)

All conversions run entirely in your browser — nothing is sent to a server. Factors are exact wherever an exact definition exists.