Time Duration Calculator
Find the exact duration between two times — perfect for shifts, timesheets, and schedules.
What Is the Time Duration Calculator?
Time Duration Calculator Formula
Duration = End Time − Start Time (in minutes since midnight)
How Is the Time Duration Calculator Calculated?
Both times are converted to total minutes since midnight (hours × 60 + minutes), then subtracted to get the duration in minutes. For overnight shifts, checking "ends next day" adds 24 hours (1440 minutes) to the end time before subtracting, correctly handling durations that cross midnight.
Time Duration Calculator Example
From 9:00 AM to 5:30 PM: duration = 8 hours 30 minutes (8.5 decimal hours) — a typical full workday with a half-hour built in.
How to Use the Time Duration Calculator
Step 1
Enter the start time.
Step 2
Enter the end time.
Step 3
Check "ends next day" if the end time is on the following day (e.g. an overnight shift).
Step 4
Click Calculate Duration to see the total time elapsed.
Benefits
- Correctly handles overnight durations that cross midnight.
- Shows results in hours+minutes, decimal hours, and total minutes.
- No manual clock arithmetic or unit conversion needed.
Common Time Duration Calculator Scenarios
Scenario 1
Calculating work shift lengths for timesheets or payroll.
Scenario 2
Finding cooking, workout, or travel duration between two clock times.
Scenario 3
Checking how long a meeting or event lasted.
Understanding Your Result
The duration is the exact elapsed time between your two times. Decimal hours (e.g. 8.5 instead of 8h 30m) are especially useful for payroll systems that calculate wages based on fractional hours.
Tips
- Use decimal hours when entering time into payroll or invoicing software.
- Always check "ends next day" for shifts that start in the evening and end after midnight.
- Double-check AM/PM if your browser's time picker displays a 12-hour clock.
Common Mistakes
- Forgetting to check "ends next day" for overnight shifts, which produces a negative or incorrect duration.
- Mixing up start and end times, reversing the calculation.
- Assuming the result is in decimal format when it's shown as hours and minutes, or vice versa.
Frequently Asked Questions
How do I calculate an overnight shift, like 10 PM to 6 AM?
Enter 22:00 as the start time and 06:00 as the end time, then check "ends next day" — the calculator will correctly return 8 hours.
What are decimal hours used for?
Decimal hours (like 7.5 instead of 7h 30m) are commonly used in payroll and invoicing systems that calculate pay based on fractional hours worked.
Can I use this for cooking or workout durations?
Yes, enter any start and end time to find the duration — it works for any activity, not just work shifts.
Why did I get an error saying end time must be after start time?
This happens when the end time is earlier than the start time and "ends next day" isn't checked — enable that option for any duration that spans past midnight.
Can I calculate duration across multiple days, not just within 24 hours?
Check whether the tool supports entering full dates alongside times — if it's time-only, it's designed for single-day or overnight (crossing midnight) spans rather than multi-day durations.
What's a decimal hours format, and why would I need it?
Decimal hours express partial hours as a decimal (like 7.5 instead of 7 hours 30 minutes) — commonly needed for payroll systems and timesheets that calculate pay based on decimal hour values.
Does this calculator round the duration result?
Check the specific output format — many duration calculators show exact hours and minutes without rounding, though decimal hour conversions may round to two decimal places for readability.
Can I use this to calculate break time deductions from a shift?
Calculate the full shift duration first, then subtract your break duration separately, since this calculator finds the raw time between two points rather than automatically deducting breaks.
Is there a limit to how long a duration this calculator can compute?
It's designed for calculating within a single day or overnight span — for durations spanning many days or weeks, use the Date Add/Subtract or Age calculator instead.
Important Information
Times are based on your browser's local time input and do not account for timezone changes.
Last updated: July 26, 2026