Time Duration Calculator
Find the duration in hours and minutes between two clock times, with automatic rollover when the end time is past midnight. Useful for shift work, meeting and study sessions, travel times, exercise timing, and any 'how long was X to Y?' question that doesn't involve subtracting a break.
Last Updated: June 2026
Who this calculator helps
- Workers totaling a single shift's clock-in to clock-out duration.
- Students timing a study or revision block.
- Travelers and commuters checking trip durations across departure and arrival times.
- Cooks tracking how long a slow-cook recipe or proof actually took.
- Athletes and trainers timing workouts, runs, or rest intervals.
Duration
8h 30m
8.50 hours · 510 minutes
All calculations are estimates based on average platform fees. Real profits may vary depending on category, ads, and shipping.
How to use this calculator
- Enter your numbers in each field above — the calculator updates instantly as you type, so there's nothing to submit.
- Use your real figures when you have them, or sensible estimates while you're planning. If a field doesn't apply, leave it at zero.
- Compare the results, then change one input at a time to see how each lever (price, cost, fees, volume) moves the outcome.
When to use this calculator
- You have a start and end time on the same day (or one that crosses midnight) and want a clean hours-and-minutes total.
- You want decimal hours for a quick mental check, not a full timesheet.
- You're comparing how long two activities took, side by side.
Formula
Duration = End time − Start time (add 24h if end is earlier than start)
Worked example
Start 09:00, end 17:30.
- End minutes since midnight: 17 × 60 + 30 = 1050
- Start minutes: 9 × 60 = 540
- Difference: 1050 − 540 = 510 min = 8h 30m
Answer: 8 hours 30 minutes
More worked examples
Night shift: clock in 22:00, clock out 06:30 the next morning.
- End (06:30) is before start (22:00), so add 24 hours: 06:30 + 24:00 = 30:30 reference.
- End minutes: 30 × 60 + 30 = 1830
- Start minutes: 22 × 60 = 1320
- Difference: 1830 − 1320 = 510 minutes = 8h 30m
Answer: 8 hours 30 minutes
Movie starts 19:45, ends 22:10.
- End minutes: 22 × 60 + 10 = 1330
- Start minutes: 19 × 60 + 45 = 1185
- Difference: 1330 − 1185 = 145 minutes = 2h 25m
Answer: 2 hours 25 minutes
A short focus block from 14:50 to 15:15.
- End minutes: 15 × 60 + 15 = 915
- Start minutes: 14 × 60 + 50 = 890
- Difference: 25 minutes
Answer: 0 hours 25 minutes
How it works
Both times are converted to minutes since midnight, then subtracted. Working in plain minutes avoids fiddly hours-and-minutes arithmetic and keeps the result exact.
When the end time is earlier than the start time, the calculator adds 24 hours so an overnight shift like 22:00 to 06:00 returns 8 hours instead of a negative number.
The result is shown in both 'h Xm' and decimal hours. Decimal hours are the format most payroll, billing, and scheduling tools expect — 8h 30m is 8.50 hours.
This tool measures elapsed clock time only — it doesn't subtract breaks. For timesheet math with a break, use the Hours Worked Calculator on this site.
Expert tips
- Decimal hours make multiplication easier. To estimate gross pay quickly, multiply decimal hours by your hourly rate. For a richer view, use the Hourly to Salary calculator.
- If you're timing more than 24 hours (a long event or a multi-day shift), split it into separate calculations per day and add them up.
- Set your phone's clock to 24-hour format when you're entering many shifts — it removes any AM/PM ambiguity.
- Some payroll systems expect time as hh:mm and others as decimal. Note which yours uses before pasting the result.
- When timing a meeting or appointment, add a few minutes of buffer before/after to account for the real start and end.
How to interpret your results
- Dollar values are shown per sale, per order, or per item unless a result is explicitly labelled monthly, weekly, or daily.
- Percentages (margin, ROI, conversion rate) are easier to compare across products and price points than raw dollars — use them when you benchmark.
- A positive result means you're ahead after the costs and fees you entered. A negative result means the current numbers don't work — change a lever (raise price, cut a cost, lower ad spend) and recalculate.
- Treat the output as a planning estimate, not a guarantee. Fees, taxes, and conversion rates shift over time — re-run the numbers whenever a key input changes.
Limitations
- The calculator does not subtract breaks. Use the Hours Worked Calculator when an unpaid break needs to come out.
- It does not handle durations longer than 24 hours in one calculation — break long spans into per-day chunks.
- It works at minute precision; seconds are not supported.
Common mistakes
- Mixing 12-hour AM/PM with 24-hour entries and forgetting which one the device is using.
- Expecting the duration to subtract a lunch break — this tool measures raw end-minus-start time.
- Typing invalid times like 25:00 or 12:75 — the time field rejects them.
- Assuming a shift that runs 23:00 to 00:30 returns 30 minutes — the calculator correctly rolls past midnight and returns 1h 30m.
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FAQ
- How do I include a break?
- Use the Hours Worked Calculator instead — it subtracts a break from the duration.
- Does it handle 12-hour times?
- Yes. Browser time inputs accept 12- or 24-hour entry depending on your device settings.
- What if end is before start?
- The calculator assumes the end time is on the next day and adds 24 hours, which is what you want for night shifts.
- Does it count seconds?
- No — clock-time inputs are limited to hours and minutes for everyday use.
- Is the result rounded?
- The minutes value is exact. The decimal hours figure is rounded to two decimals for readability.
- How do I get total time across a week?
- Run this calculator (or the Hours Worked Calculator) once per shift and add the decimal-hours values together.
- Can I use it for a multi-day event?
- It handles overnight spans up to 24 hours. For longer events, calculate one calendar day at a time and add the totals.
- How is this different from the Hours Worked Calculator?
- Time Duration is raw end-minus-start time. Hours Worked also subtracts an unpaid break, which is what payroll typically needs.
- Why does my answer show 8.50 instead of 8:30?
- 8.50 is the decimal-hour form of 8 hours and 30 minutes (0.50 × 60 = 30 minutes). Most payroll tools want the decimal form.
- Does daylight-saving time affect the result?
- No — the calculator does not adjust for DST. Adding or losing an hour on a real-world DST day would change the elapsed time by an hour in either direction; if that matters, calculate before and after the transition separately.
Why trust this calculator?
This tool uses standard mathematical formulas and commonly accepted calculation methods, shown openly in the Formula section above so you can verify the math yourself. Results are estimates based on the information you enter and do not account for every individual circumstance. For important financial, tax, legal, medical, or business decisions, please double-check with a qualified professional before acting on the numbers.
Keep going
One calculator rarely tells the full story. Pair this one with a related tool below to pressure-test your numbers from a different angle, or browse Time & Date Calculators for more in the same category.
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