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Time Unit Converter

Convert time between seconds, minutes, hours, days, weeks, and years.

To
Every unit
  • 5,400,000,000,000
    Nanoseconds
    ns
  • 5,400,000
    Milliseconds
    ms
  • 5,400
    Seconds
    s
  • 90
    Minutes
    min
  • 1.5
    Hours
    h
  • 0.0625
    Days
    d
  • 0.0089
    Weeks
    wk
  • 0.0021
    Months (average length)
    mo
  • 0.0002
    Years (average length)
    yr
Months and years are approximations. A month is treated as 30.436875 days and a year as 365.25 days, which are the long-run averages. Real calendar months run 28 to 31 days and real years run 365 or 366, so use a date tool when the exact dates matter.
Precision4 places

How to convert time units

  1. Enter a duration

    Type the number you want to convert into the field on the left.

  2. Pick the two units

    Choose the unit your value is in, then the unit you want it converted to.

  3. Read the result

    The converted value appears instantly, with every other supported unit listed below it.

  4. Copy what you need

    Copy the headline result, or use the copy button on any row to grab a single unit.

Why use this tool

Nine units in one place

Nanoseconds, milliseconds, seconds, minutes, hours, days, weeks, months, and years all convert from a single value.

Honest about months and years

A month is treated as 30.436875 days and a year as 365.25 days. Both are averages, and the tool says so next to the results.

Both directions at once

Pick a from unit and a to unit, then swap them with one tap when you need the reverse conversion.

Adjustable precision

Show whole numbers for a quick read, or up to six decimal places when sub-second durations matter.

Runs on your device

Every calculation happens in the page as you type. Nothing is uploaded and no account is required.

About this tool

The Time Unit Converter turns one duration into every other common unit at the same time. Enter a value, choose the unit it is measured in, pick the unit you want, and the result updates as you type. A full list underneath shows the same duration in nanoseconds, milliseconds, seconds, minutes, hours, days, weeks, months, and years.

Everything up to a week is exact. A minute is 60 seconds, an hour is 3,600, a day is 86,400, and a week is 604,800. Those factors never change, so a conversion between any two of them is precise to the last decimal you ask for.

Months and years are different, and this is where most converters quietly mislead. A calendar month runs anywhere from 28 to 31 days, and a year is 365 days except in leap years when it is 366. There is no single correct factor. This tool uses 30.436875 days for a month, which is the average calendar month across a full 400 year cycle, and 365.25 days for a year, which is the usual average including leap years. Both are flagged as averages in the results list and in a note under it. If you need the real gap between two specific dates, including leap years and month lengths, that is a calendar problem rather than a unit conversion.

For date-specific work, use the date difference calculator or add or subtract days. For formatting a duration as hours and minutes, try the duration calculator.

Frequently asked questions

How many days are in a month for this converter?
It uses 30.436875 days, which is the average length of a calendar month across a full 400 year cycle. That is an approximation, not a real month, because real months run 28 to 31 days.
Why is a year 365.25 days here?
Because a leap year adds a day roughly every four years, so the long-run average is close to 365.25 days. A specific year is either 365 or 366 days, so use a date tool if you need the exact span between two dates.
Which conversions are exact?
Everything from nanoseconds up to weeks. A minute is exactly 60 seconds, an hour 3,600, a day 86,400, and a week 604,800. Only months and years rely on an average.
Can I convert very small durations?
Yes. Nanoseconds and milliseconds are included, and any result past a quadrillion or below a millionth is shown in exponent notation so it stays readable.
Are my numbers sent anywhere?
No. All conversion happens on your device inside the page. Nothing you type is uploaded or stored.

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