Time Calculator

Calculate time duration, add/subtract time, convert time formats, and perform time arithmetic. Perfect for scheduling, time tracking, and time calculations.

Time Calculator

Time Calculation Results

Enter your times to calculate duration

How to calculate time (hours & minutes)

When you need to calculate time between a start and finish — a shift, study block, or drive — convert each clock time to minutes past midnight, subtract, then convert back. If the end time is earlier than the start (night shift), add 24 hours before subtracting. This calculator does that for you and also shows decimal hours (e.g. 7.5) which Australian payroll systems often expect.

Example: 09:15 to 17:45 is 8 hours 30 minutes (8.50 decimal hours). Use Add Time to push a start time by a break length, or Subtract Time to work backwards from a deadline. For pure “hours:minutes → decimal” conversion, use the time-to-decimal calculator linked below.

Calculation Types

  • Duration: Calculate time between two times
  • Add Time: Add time to a base time
  • Subtract Time: Subtract time from a base time
  • Convert: Convert time to different formats

Common Uses

  • Work Hours: Calculate work duration
  • Payroll: Convert to decimal hours
  • Scheduling: Plan meeting durations
  • Time Tracking: Track project time
  • Travel Time: Calculate journey duration

How to calculate time between two clock times

Convert each time to minutes past midnight, subtract (adding 24 hours if the end is next day), then convert back to hours and minutes — plus decimal hours for payroll.

  • Minutes = hours × 60 + minutes
  • Duration minutes = end − start (or end + 1440 − start overnight)
  • Decimal hours = total minutes ÷ 60

Worked example: calculate time from 09:15 to 17:45

  1. Start = 9×60+15 = 555 minutes; end = 17×60+45 = 1065 minutes.
  2. Duration = 1065 − 555 = 510 minutes.
  3. 510 ÷ 60 = 8 hours 30 minutes (8.50 decimal hours).
  4. Use Add/Subtract modes to shift a shift start by a break or overtime block.

Frequently Asked Questions

How do I calculate time between two times?
Enter start and end in HH:MM, choose Duration, and tap Calculate. You get hours, minutes, total minutes and decimal hours.
Does it handle overnight shifts?
Yes. If the end time is earlier than the start, the calculator treats it as crossing midnight.
What are decimal hours for?
Payroll systems often need hours as decimals (e.g. 7.5 instead of 7:30). See also our time-to-decimal calculator.
Can I add or subtract time?
Yes. Use Add Time or Subtract Time to move a base clock time by a duration.