Time Calculator
Add up hours and minutes, subtract times, or find what time it will be after a duration. Works with 1:30, 1h 30m or 1.5 hours.
- Add & subtract
- Clock time ±
- Decimal hours
- Flexible input
Time calculator
Formats: 1:30 (h:mm), 1:30:15, 2h 15m, 45m, 90s, or 1.5 (hours).
4:15
4 hours 15 minutes.
- Decimal hours
- 4.25
- Total minutes
- 255
- Days, hours, minutes
- 0d 4:15
What is a time calculator?
A time calculator adds and subtracts amounts of time. It is useful when minutes run past 60, which makes normal calculators awkward: 2:45 plus 1:30 is 4:15, not 3.75 or 4.15. This calculator totals a list of durations, subtracts times, and adds a duration to a clock time to answer questions like “what time will it be 8 hours 30 minutes after 9:15 AM?”.
How to use Time Calculator
- Choose “Add durations” to total times, or “Clock time ±” to move a clock time forward or back.
- Type times as 1:30, 1:30:15, 2h 15m, 45m or 1.5.
- Use the + and − buttons to add or subtract each row, and “Add another time” for more rows.
- Read the total in hours and minutes, decimal hours and total minutes.
Adding time by hand
- Add minutes first. If they reach 60 or more, carry 1 hour: 45 + 30 = 75 minutes = 1 hour 15 minutes.
- Then add the hours, including the carried hour: 2 + 1 + 1 = 4, giving 4:15.
- To convert to decimal hours, divide minutes by 60: 4:15 = 4.25 hours.
- Clock times wrap at midnight: 9:15 PM plus 5 hours is 2:15 AM the next day.
Why use this time calculator
- Understands how you typeh:mm, h:mm:ss, “2h 15m”, minutes only, or decimal hours.
- Any number of rowsTotal a whole list of video clips, tasks or laps.
- Clock arithmeticFind finish times and handle crossing midnight.
- Private by defaultEverything is calculated in your browser. Dates, times and pay rates are never sent to a server.
Common uses
- Billing and timesheets. Add up task durations and convert to decimal hours.
- Video and audio. Total the length of clips or tracks.
- Sport and training. Add lap or interval times.
- Travel. Work out arrival times from a departure time and flight duration.
More time and date tools: date calculator, days between dates, business days, age calculator, hours calculator, time card, military time, time zones.
Example: a shift finishing time
You start at 9:15 AM and need to work 8 hours 30 minutes. Choose “Clock time ±”, enter 9:15 AM and 8:30: you finish at 5:45 PM, which is 17:45 on a 24-hour clock.
What to expect from the result
Durations are shown up to seconds. Clock calculations use a 24-hour day and ignore daylight-saving changes. For the time between two clock times, use the hours calculator.
Time Calculator questions
How do I add hours and minutes?
Enter each time as h:mm, such as 2:45 and 1:30. The calculator adds them and carries minutes over 60, giving 4:15.
How do I subtract time?
Click the + button next to a row to switch it to −. That row is subtracted from the total.
What time will it be after a certain number of hours?
Choose “Clock time ±”, enter the start time and the duration, and read the resulting time. It shows if the result is on the next day.
How do I convert hours and minutes to decimal?
Divide the minutes by 60 and add the hours. 7:45 is 7 + 45 ÷ 60 = 7.75 hours. The calculator shows this automatically.
Can I enter seconds?
Yes. Use h:mm:ss, such as 1:02:30, or units like 90s.