Time Converter

Time Unit Converter

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Free Online Time Unit Converter

Whether you need to know how many seconds are in a year or how many hours are in a week, our free time unit converter handles every conversion instantly. Simply enter a value, choose your starting unit, and get the equivalent across all time units at once — no formula memorization required.

Supported Time Units

This tool converts between seconds, minutes, hours, days, weeks, months (based on a 30-day month), and years (based on a 365-day year). All conversions happen client-side in your browser without any page reload.

A Brief History of Time Measurement

The division of a day into hours, minutes, and seconds has ancient roots. The Babylonians used a base-60 (sexagesimal) number system, which is why we have 60 seconds in a minute and 60 minutes in an hour. The concept of the second as 1/86,400 of a mean solar day was formalized by the International System of Units (SI) in 1967, redefining it based on atomic transitions of caesium-133. Today, atomic clocks keep time accurate to within a few billionths of a second per day.

Common Conversion Reference

  • 1 minute = 60 seconds
  • 1 hour = 3,600 seconds = 60 minutes
  • 1 day = 86,400 seconds = 24 hours
  • 1 week = 604,800 seconds = 168 hours
  • 1 month (30 days) = 2,592,000 seconds = 720 hours
  • 1 year (365 days) = 31,536,000 seconds = 8,760 hours

Practical Uses of Time Conversion

Time conversions are needed in a wide range of everyday and professional situations. Software developers calculate timeouts and expiry windows in milliseconds or seconds. Project managers track durations in weeks and months. Scientists working with decay rates or astronomical events often need precise conversions between days and years. Athletes and coaches analyze performance intervals in minutes and seconds. Even subscription and billing cycles rely on accurate month-to-year conversions.

Frequently Asked Questions

How many seconds are in a year?
A standard year has 365 days, which equals 31,536,000 seconds. A leap year (366 days) has 31,622,400 seconds.
How many hours are in a week?
There are exactly 168 hours in a week (7 days × 24 hours = 168).
Why does this tool use 30 days for a month?
Calendar months range from 28 to 31 days. Using 30 days is the standard approximation for general time conversion purposes. For exact calendar calculations, use the Time Duration Calculator instead.
Can I convert decimal values?
Yes. Enter values like 1.5 hours and the converter will show the equivalent in all units (e.g., 1.5 hours = 90 minutes = 5,400 seconds).
Is this converter accurate for leap years?
This converter uses a fixed 365-day year for simplicity. For leap-year-aware calculations, use the Days Between Dates calculator which works with actual calendar dates.