Time Duration Calculator
How long between two times? Enter start and end — overnight shifts handled — and stack up multiple intervals.
Duration
Intervals
No intervals added yet.
How to use the time duration calculator
- Pick a start time and an end time.
- The duration appears instantly in hours/minutes, total minutes, and decimal hours.
- Click "Add this interval" to stack it in the list — the combined total updates automatically.
- Remove any interval with its remove button.
Time tracking tips
Decimal hours are what payroll systems want: 7 hours 30 minutes is 7.5, and 8 hours 45 minutes is 8.75 — just divide the minutes by 60. If you work overnight, enter the end time as-is (for example, start 22:00, end 06:00) and the calculator rolls past midnight automatically. For billing, round consistently: most freelancers round each entry to the nearest quarter hour, but always round in the client's favor on small entries to avoid disputes. Logging intervals through the day instead of reconstructing them at night is dramatically more accurate — memory underestimates focused work by 20% or more.
Frequently asked questions
Does it handle overnight shifts?
Yes. If the end time is earlier than the start time, it assumes the shift crossed midnight and adds 24 hours.
What are decimal hours?
Hours expressed as a decimal — 1 hour 30 minutes is 1.5. Payroll and billing systems usually require this format.
Can I total a whole week?
Yes — add each day as an interval and the combined total sums them all.
Why do start and end need dates?
They do not — this calculator works on clock times only, which is all you need for shift and session lengths.