Time Converter - Seconds, Minutes, Hours, Days & Years

About the Time Converter

Time units are familiar, but they are awkward to convert because they do not step by tens. Sixty seconds make a minute, sixty minutes an hour, twenty-four hours a day and seven days a week. Working out how many hours are in a year, how long a million seconds really is, or how many weeks a project of 200 days spans means a chain of multiplications and divisions that is easy to slip on.

This time converter converts between seconds, minutes, hours, days, weeks and years. It shows the result, the exact factor both ways, the time in every other unit, and a breakdown into years, days, hours, minutes and seconds, so a figure such as 11.5741 days becomes 11 days, 13 hours, 46 minutes and 40 seconds.

How to Use the Time Converter

Enter the amount of time.

Choose the unit to convert from and to.

The result appears with the factor, the time in every unit, and the breakdown.

How Time Conversion Works

Every unit is converted through the second:

  1 minute = 60 s
  1 hour   = 60 min  = 3,600 s
  1 day    = 24 h    = 86,400 s
  1 week   = 7 days  = 604,800 s
  1 year   = 365.25 days = 31,557,600 s   (average, including leap years)

  result = value × (from-unit in seconds) ÷ (to-unit in seconds)

Step-by-Step Example

One million seconds to days.

  1,000,000 ÷ 86,400 = 11.5741 days
  Breakdown:  11 days = 950,400 s, leaving 49,600 s
              49,600 s = 13 h (46,800 s), leaving 2,800 s
              2,800 s = 46 min (2,760 s), leaving 40 s

So a million seconds is about 11.5741 days, or 11 days 13 hours 46 minutes 40 seconds — well under two weeks. A billion seconds, by contrast, is about 31.7 years.

One year to hours is 365.25 × 24 = 8,766 hours.

Quick Reference

  1 hour  = 3,600 seconds        1 day  = 1,440 minutes
  1 week  = 168 hours            1 week = 10,080 minutes
  1 year  = 8,766 hours          1 year = 525,960 minutes
  1 year  = 52.1786 weeks        1,000 hours = 41.6667 days

Decimal Hours

Timesheets, invoices and flight logs often record time in decimal hours, where 7.5 hours means 7 hours 30 minutes, not 7 hours 50 minutes. To turn minutes into a decimal, divide by 60: 45 minutes is 0.75 hours, and 20 minutes 0.333 hours. To go back, multiply the decimal part by 60: 2.4 hours is 2 hours 24 minutes. This is one of the most common time mistakes, and the converter's breakdown makes it easy to check.

Why Years Are 365.25 Days

The Earth takes about 365.2422 days to go round the Sun. Calendars keep in step by adding a leap day most fourth years. The Julian year of exactly 365.25 days, the average of three 365-day years and one 366-day year, is the standard year used in astronomy and in this converter. The Gregorian calendar we use today refines this slightly by skipping three leap days every 400 years, giving an average of 365.2425 days. For exact dates, such as ages, deadlines or contract periods, use a date calculator that counts real calendar days.

Why Months Are Left Out

Months range from 28 to 31 days, so "a month" has no fixed length. An average month is 365.25 ÷ 12 = 30.4375 days, which is fine for rough planning — for example, estimating that 6 months is about 26 weeks — but not for exact arithmetic. Counting whole calendar months is a job for a date calculator.

Very Short and Very Long Times

Seconds divide further into milliseconds (thousandths), microseconds (millionths) and nanoseconds (billionths). Computers and physics work at those scales; light travels about 30 centimetres in a nanosecond. For very long times, the same year factor applies: a century is 3,155,760,000 seconds, and the converter switches to readable powers of ten for extreme values.

Working Time and Billing

Many conversions of time are really about work. A standard full-time year of 40 hours a week for 52 weeks is 2,080 hours, the figure often used to turn a salary into an hourly rate. Subtracting holidays and public holidays usually leaves around 1,800 to 1,900 working hours. Freelancers and consultants billing by the hour convert between minutes, decimal hours and days all the time: a 7.5-hour working day means 37.5 hours in a five-day week, and a project estimated at 150 hours is 20 such days, or four working weeks.

Time Zones and Clocks

Converting units of time is different from converting between time zones. A time zone changes the clock reading, not the length of time: a 9-hour flight is 9 hours long whatever the clocks say at each end. Similarly, a 24-hour clock reading such as 17:45 is simply 5:45 pm, not a duration. For durations between two clock times, subtract the start from the end, adding 24 hours if the period crosses midnight.

Understanding Your Result

The headline is the converted time.

The conversion factor shows the factor both ways.

The in every unit line gives the time in all six units.

The also line breaks the time into years, days, hours, minutes and seconds.

When Should You Use This Calculator?

Use it to convert durations for projects, schedules and planning.

Use it to turn large numbers of seconds or minutes into days and hours.

Use it with timesheets and decimal hours.

Use it for science and computing, where times are given in seconds.

Common Mistakes

Treating decimal hours as minutes. 1.5 hours is 1 hour 30 minutes, not 1 hour 50.

Using 365 days for every year. Over long periods, leap years add about a quarter of a day a year.

Converting months exactly. Months vary; use an average only for estimates.

Forgetting daylight saving. A clock day can be 23 or 25 hours when clocks change.

Mixing calendar and elapsed time. Deadlines depend on dates, not just durations.