Time Duration Calculator

Find how long there is between two times of day. Enter a start time and an end time and the calculator shows the duration in hours, minutes and seconds, with overnight spans handled, plus the total in decimal hours and in minutes. Free and instant in your browser.

  • Leap-year accurate
  • 100% free
  • No sign-up, no app
  • Instant as you type
  • Works offline after first load
Read the guide: How to Calculate Hours Between Two Times
Duration
8h 30m
Same-day span.
Decimal hours
8.50
Total minutes
510
Total seconds
30,600

How to use it

  1. 1

    Enter the start time

    Pick the time the period begins, such as a shift start or an event time.

  2. 2

    Enter the end time

    Pick the time it ends. If the end is earlier, the calculator assumes the period runs past midnight.

  3. 3

    Read the duration

    See the hours, minutes and seconds, and the same span as decimal hours for timesheets.

When it comes in handy

Shifts and timesheets

Work out hours worked between a clock-in and a clock-out, including overnight shifts.

Billing by the hour

Get the decimal hours for an invoice, such as 1.5 hours for ninety minutes.

Cooking and tasks

Measure how long something ran between a start and an end time.

Instant, accurate & 100% in your browser

The calculation runs right here in your browser, counting the real calendar so leap years and month lengths come out right. Nothing you type is sent to a server, there is no sign-up and no limit, and once the page has loaded it keeps working even with no connection.

Frequently asked questions

How does it handle a shift that crosses midnight?
If the end time is earlier in the day than the start, the calculator assumes the period continues into the next day. So 22:00 to 06:00 is counted as eight hours rather than a negative span. This matches how overnight shifts are read.
What are decimal hours used for?
Decimal hours express the duration as a single number, so ninety minutes becomes 1.5 hours. Many timesheets and billing systems use this format because it is easy to multiply by an hourly rate. The calculator shows it alongside the hours and minutes.
Does it count seconds?
Yes. You can enter times to the second, and the duration includes the seconds in the breakdown and in the total. If you only enter hours and minutes, the seconds simply show as zero.
Does this work offline and is anything sent to a server?
The calculation runs entirely in your browser, so nothing you type is sent anywhere, and once the page has loaded it keeps working with no connection. There is no sign-up and no limit on how many dates you check.

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