Time Converter
Convert seconds, minutes, hours, days, weeks, months and years — using the average Gregorian month and year so long spans stay accurate. Results update as you type; exact factors shown.
One hour is 60 minutes — see the exact factor, not a rounded rule of thumb.
How the time converter works
Time converts through the second. Minutes, hours, days and weeks are exact multiples. A month is taken as the Gregorian average (30.436875 days) and a year as the Gregorian average (365.2425 days = 31,556,952 s); calendar months and leap years vary from these averages.
The US uses customary units (US gallon, short ton, °F) in daily life; NIST SP 811 gives the exact SI factors.
Common time conversions
| From | To | Units |
|---|---|---|
| 1 d | 24 h | day to hours |
| 1 wk | 168 h | week to hours |
| 1 yr | 365.2425 d | year (365.2425 days) to days |
| 1 yr | 8,765.82 h | year (365.2425 days) to hours |
| 1 mo | 30.4369 d | month (average, 30.4369 days) to days |
| 1,000 s | 16.6667 min | seconds to minutes |
| 8 h | 480 min | hours to minutes |
| 1 h | 3,600 s | hour to seconds |
| 100 d | 14.2857 wk | days to weeks |
| 1 yr | 31,556,952 s | year (365.2425 days) to seconds |
Units in this converter and their exact factors
| Unit | Symbol | One unit in seconds |
|---|---|---|
| millisecond | ms | 0.001 second |
| second | s | 1 second |
| minute | min | 60 second |
| hour | h | 3,600 second |
| day | d | 86,400 second |
| week | wk | 604,800 second |
| month (average, 30.4369 days) | mo | 2,629,746 second |
| year (365.2425 days) | yr | 31,556,952 second |
FAQFrequently asked questions about time conversion
How many hours are in a year?
About 8,766 hours on the Gregorian average (365.2425 days); a common year has 8,760 hours, a leap year 8,784.
How many seconds are in a day?
Exactly 86,400.
How many weeks are in a year?
52 weeks and one day (two in a leap year) — about 52.18 weeks on average.
How many days are in a month on average?
30.44 days (365.2425 / 12).
How many minutes are in a week?
10,080 minutes.
Where these figures come from
- BIPM — The International System of Units (SI Brochure, 9th edition) — definitions of the base and derived units.
- NIST Special Publication 811 — Guide for the Use of the International System of Units — the exact conversion factors used here.
- National Institute of Standards and Technology (NIST) — United States's national measurement authority.
Last checked: September 2026. Conversion factors are fixed by definition and do not change with tax years or regulations.