Time Calculator
Find the hours between two times, add up durations, add time to a clock time or convert to decimal hours. Overnight shifts and breaks included.
Enter a start and an end time. If the end is earlier than the start, it’s treated as an overnight shift that ends the next day.
Type durations one per row — the total updates as you go. Tap the + next to a row to subtract it instead.
Add or subtract hours and minutes from a time. The result is right even when it rolls into the next or previous day.
Type in either box and the other fills in. Handy for timesheets and payroll, which use decimal hours.
How to use the time calculator
- Pick a tab: Between times, Add durations, Add to a time or Decimal hours.
- Type times like 9:30, 930 or 9.30 and set AM/PM with the button next to the field — or tap Now for the current time. Prefer 17:30? Tick 24-hour clock.
- For a timesheet, enter your unpaid break in minutes, then use Add to list to collect each day and see the weekly total.
- Results update as you type, in hours and minutes, decimal hours and total minutes. Use Copy result to paste them anywhere.
How to calculate time and hours
Time is counted in base 60: an hour has 60 minutes and a minute has 60 seconds. That’s why adding and subtracting times like ordinary numbers goes wrong. To subtract 9:45 from 17:30, compare the minutes first; 30 is less than 45, so you borrow an hour: 90 − 45 = 45 minutes and 16 − 9 = 7 hours, for 7 hours 45 minutes. The time calculator does this borrowing and carrying for you.
Overnight shifts
If the end time is earlier than the start time, the shift ends the next day, so 24 hours are added to the end: a 10:00 PM to 6:00 AM shift is (6 + 24) − 22 = 8 hours. The calculator spots this automatically, labels the result “next day” and draws the shift across midnight on the 24-hour bar. The same start and end (say 7:00 AM to 7:00 AM) counts as a full 24 hours.
Subtracting breaks
Hours worked are the time between clocking in and out, minus unpaid breaks. Someone working 8:30 AM to 5:00 PM with a 30-minute lunch has worked 8 hours, not 8½. Enter 30 or 0:30 in the break field and the result shows both the time worked and the time including the break.
Why decimal hours?
Payroll software, timesheets and invoices usually want hours as a decimal so they can be multiplied by an hourly rate. To convert, divide minutes by 60: 15 minutes is 0.25, 30 minutes is 0.5 and 45 minutes is 0.75 hours, so 7 hours 45 minutes = 7.75 hours. To go back, multiply the decimal part by 60: 8.4 hours = 8 hours 24 minutes. The Decimal hours tab works both ways, and the table beside the tool lists common values.
Adding up hours worked
Type each day into Add durations to get a weekly or monthly total. Minutes roll over into hours automatically, and totals over 24 hours are also shown in days. In the United States, the Fair Labor Standards Act generally requires overtime pay for non-exempt employees after 40 hours in a workweek, so a quick weekly total is worth checking. Flip a row’s + to − to subtract time, such as an unpaid meeting.
Adding time to a clock time
Questions like “If I go to bed at 10:30 PM, what time is it after 7 hours 45 minutes of sleep?” are what Add to a time is for. The answer is 6:15 AM the next day. Use it the same way for medication schedules, cooking times or when a long meeting will end.
Everything runs in your browser — the times you enter are never sent to a server.
Frequently asked questions
How do I calculate the hours between two times?
Subtract the start time from the end time. If the minutes go negative, borrow 1 hour and add 60 to the minutes. For example, 5:30 PM − 9:45 AM = 7 hours 45 minutes. In this calculator, just enter both times and the answer appears instantly.
How do I calculate an overnight shift?
If the end time is earlier than the start, add 24 hours to the end before subtracting: 10:00 PM to 6:00 AM is (6 + 24) − 22 = 8 hours. The calculator detects shifts that cross midnight automatically.
How do I convert minutes to decimal hours?
Divide the minutes by 60: 15 min = 0.25, 30 min = 0.5, 45 min = 0.75 hours. So 7 hours 45 minutes is 7.75 hours. To convert back, multiply the decimal part by 60: 0.4 hours = 24 minutes.
How do I add up my hours worked for the week?
Use the Add durations tab and enter each day as hours and minutes; the total and its decimal value update instantly. From the Between times tab, Add to list drops each day’s result into that list with one tap.
Are the times I enter saved?
Your values are stored only in this browser on this device, so they’re still there next time. Nothing is sent to a server. Use Clear to remove them at any time.