Time Unit Converter
Convert between seconds, minutes, hours, days, weeks, months, and years instantly.
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How to use this calculator
- 1
Enter the time value you want to convert.
- 2
Select the unit you are starting from (e.g. hours).
- 3
Select the unit you want to convert to (e.g. minutes).
- 4
The result appears instantly.
Frequently asked questions
How many seconds are in a day?
There are 86,400 seconds in a day (60 seconds × 60 minutes × 24 hours).
How many hours are in a year?
A standard year has 8,760 hours (365 days × 24 hours). A leap year has 8,784 hours.
How many milliseconds are in a second?
There are exactly 1,000 milliseconds in one second.
How many weeks are in a year?
A year has 52 weeks and 1 day (or 2 days in a leap year), totalling exactly 52.1775 weeks on average.
How long is a nanosecond?
A nanosecond is one billionth of a second (10⁻⁹ s). In that time, light travels about 30 centimetres — roughly one foot.
Time unit conversion explained
How to use the time unit
Use this time unit to onvert between seconds, minutes, hours, days, weeks, months, and years instantly. Enter your values above and get your result in seconds. The tool is free, works on all devices, and keeps your data private — nothing is stored or shared.
How the time unit works
The time unit converter uses standard formulas used in unit conversion in science, engineering, cooking, and everyday use. Enter your inputs, and the tool calculates the result instantly in your browser. No server-side processing means your data stays on your device. Results update in real time as you change inputs.
SI and everyday time units
The SI base unit of time is the second. All other units — milliseconds, minutes, hours, days — are derived from it. The second is defined by the vibration of caesium-133 atoms (9,192,631,770 cycles per second), making it one of the most precisely defined units in science.
Key time conversion facts
1 minute = 60 seconds | 1 hour = 3,600 seconds | 1 day = 86,400 seconds | 1 week = 604,800 seconds | 1 year = 31,536,000 seconds (365 days) | 1 millisecond = 0.001 seconds | 1 microsecond = 0.000001 seconds.
When time conversions are needed
Time unit conversions are common in programming (converting timestamps), science experiments (measuring reaction times in milliseconds), project management (estimating hours vs days), payroll calculations (hours worked vs days), and data analysis (log file timestamps).
Time unit: how it works
Unit conversion matters across engineering, science, cooking, and everyday life. This tool applies internationally recognised conversion factors to deliver precise, instant results across all major unit systems — no manual lookup needed.
Who uses this tool?
Scientists, engineers, chefs, and international travellers use this tool daily to bridge the gap between different measurement systems. It eliminates the need to memorise conversion factors or hunt through reference tables.
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