Time Calculator
Add and subtract hours, minutes and seconds, convert hh:mm to decimal hours, and find the time X hours from now
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Adds and subtracts hours and minutes, finds the clock time a duration before or after a given time, and the time between two clock times. It also converts hh:mm to decimal hours.
How to use
- On "Add and subtract", type one time per row, such as 1:30, 1h 30m or 90 min. The button before each row switches between adding and subtracting.
- The total appears in h:mm:ss, decimal hours, minutes and seconds. To multiply or divide it, use "Multiply or divide by".
- On "Clock times", enter a "Start time" and a "Duration" to get the end time, or use "Time between two clock times".
- On "Convert", enter one time to see it as h:mm, decimal hours, minutes, and days, hours, minutes and seconds.
How it works
- Decimal hours = hours + minutes ÷ 60, so 7 hours 45 minutes is 7.75 hours.
- A number without a unit is read as hours or minutes, as set under "A number without a unit means". Totals over 24 hours or below zero are shown as they are.
- An end time earlier than the start time is counted as the next day. Your rows and settings are saved in this browser on this device.
Questions and answers
- What is 1 hour 50 minutes plus 2 hours 20 minutes?
- 70 minutes is 1 hour 10 minutes, so the total is 4 hours 10 minutes, or about 4.17 decimal hours.
- How do I convert 7 hours 30 minutes to decimal?
- 30 ÷ 60 = 0.5, so it is 7.5 hours. Decimal hours are used to multiply hours by an hourly rate.
- How many hours are there from 10 PM to 6 AM?
- 8 hours. Enter 22:00 and 06:00 under "Time between two clock times"; the end time is earlier, so it is counted as the next day.
- Can I add up a column of times from a spreadsheet?
- Yes. Open "Paste several lines", paste one time per line and press "Read into rows". Lines starting with "-" are subtracted.