All conversions
| Unit | Value | Copy |
|---|---|---|
| Nanosecond (ns) | — | |
| Microsecond (µs) | — | |
| Millisecond (ms) | — | |
| Second (s) | — | |
| Minute (min) | — | |
| Hour (h) | — | |
| Day (d) | — | |
| Week (wk) | — | |
| Month (average) (mo) | — | |
| Year (average) (yr) | — | |
| Decade (dec) | — | |
| Century (c) | — |
How many seconds in a year? How many weeks in 1,000 hours? Convert any span of time between units from nanoseconds to centuries.
How to use the Time Unit Converter
- 1 Type a value in either box — the conversion works in both directions.
- 2 Choose the units to convert time from and to, or click any row in the table.
- 3 Use the swap button to reverse the conversion, then copy the result.
Formula
1 day = 86,400 s 1 week = 604,800 s 1 year (Gregorian average) = 365.2425 days 1 month (average) = 30.436875 days
Worked examples
Input: 1 year
Result: 31,556,952 s
Average Gregorian year
Input: 1,000 hours
Result: 41.67 days
5.95 weeks
Months and years are averages
Calendar months range from 28 to 31 days and years have 365 or 366 days, so they cannot be converted exactly. This converter uses the Gregorian averages: a year of 365.2425 days and a month of one twelfth of that (30.436875 days). For exact calendar spans, use the Date Difference Calculator.
Frequently asked questions
How many seconds are in a day?
86,400 seconds.
How many hours are in a year?
About 8,765.82 hours using the average Gregorian year (8,760 in a 365-day year).
How many weeks are in a year?
About 52.18 weeks.
Related tools
Length Converter
Convert between metres, kilometres, centimetres, millimetres, miles, yards, feet, inches and nautical miles.
Weight Converter
Convert mass between kilograms, grams, milligrams, tonnes, pounds, ounces, stones and US/UK tons.
Temperature Converter
Convert between Celsius, Fahrenheit, Kelvin and Rankine — with absolute-zero validation.
Area Converter
Convert square metres, square feet, acres, hectares, square miles, square kilometres and more.
Volume Converter
Convert litres, millilitres, cubic metres, US and UK gallons, quarts, pints, cups, fluid ounces and spoons.
Speed Converter
Convert km/h, mph, m/s, knots, ft/s and Mach.