Time Calculator
Add and subtract hours, minutes and seconds, or total a timesheet. Runs in your browser.
About this time calculator
This time calculator adds and subtracts hours, minutes and seconds, works out what the clock will say after a set duration, and totals the hours on a weekly timesheet. It is for anyone adding up shifts, video clips, workout splits or billable time.
Type times the way you would write them: 1h 30m, 90m, 1:30 or 1.5h all mean the same thing. Each line is added to a running total, and you see the answer as h:mm:ss, in plain words and in decimal hours. Hours never wrap at 24, so a week of overtime reads 52:30:00 instead of a confusing 4:30.
Need calendar dates rather than hours? The date difference calculator counts days, weeks and months between two dates.
Features
A calculator tape for time
Put one time on each line. Start a line with - to subtract it, or with * or / to multiply or divide everything above it. A table shows the running total after each line, so you can spot the entry that looks wrong.
Reads the formats people actually type
Mix 2h 15m, 1:45, 50 min, 1:30:15, 2 days 4 hours and 7.75h in one list. Clock-style input is read as h:mm or h:mm:ss. You choose what a bare number like 45 means: hours, minutes or seconds.
Every answer in four units
The total appears as h:mm:ss, as words (2d 4h 15m), and as decimal hours, minutes, seconds and days. Copy the total or the whole working with one click.
Clock time plus or minus a duration
Start at a date and time, add or subtract something like 8h 30m or 3 days 4h, and get the finishing time, its weekday and how many days later it lands.
Hours worked with breaks
Fill in start, end and unpaid break for each shift. Overnight shifts such as 22:00 to 06:00 are handled. The week totals in h:mm and decimal hours, and an optional hourly rate gives gross pay.
Shareable sums
Your list is kept in the page address, so you can bookmark it or send the link to a colleague. It runs entirely in your browser.
How to use the time calculator
- 1Pick a mode: add and subtract times, clock time plus a duration, or hours worked.
- 2Type times like 1h 30m or 1:30, or fill in start, end and break for each shift.
- 3Read the total as h:mm:ss, in words and in decimal hours, then copy it.
When to use it
Filling in a timesheet
Enter Monday to Friday with a 30-minute lunch each day and read the weekly total in decimal hours, which is what most payroll systems want. If you then want yearly or monthly pay from that hourly figure, the salary calculator converts it.
Adding up video or audio clips
Paste clip lengths such as 3:42, 12:08 and 0:55 (read as h:mm, so switch to 0:03:42 style for minutes and seconds) and see the total running time.
Planning a long drive or flight
Leave at 06:40, add 9h 25m of travel, and see that you arrive at 16:05 the same day. Add a time zone change separately with the time zone converter.
How do you add hours and minutes?
Add the minutes and the hours separately, then carry every 60 minutes into an hour. 2h 45m plus 1h 30m gives 3 hours and 75 minutes. 75 minutes is 1 hour 15 minutes, so the answer is 4h 15m.
Subtraction works the same way in reverse. If you don't have enough minutes, borrow 60 from the hours: 5h 10m minus 2h 40m becomes 4h 70m minus 2h 40m, which is 2h 30m. The calculator does this internally by turning every time into seconds, doing plain arithmetic, and converting back.
How do I convert hours and minutes to decimal hours?
Divide the minutes by 60 and add the result to the hours. The common mistake is to write 7 hours 45 minutes as 7.45. It is actually 7.75, because 45 ÷ 60 = 0.75. Paying 7.45 hours instead of 7.75 at $20 an hour loses $6 on that shift.
- 15 minutes = 0.25 hours
- 20 minutes = 0.333 hours
- 30 minutes = 0.5 hours
- 40 minutes = 0.667 hours
- 45 minutes = 0.75 hours
- To go back, multiply the decimal part by 60: 0.6 hours × 60 = 36 minutes.
What formats can I type?
Units can be short or long: w, d, h, m, s and ms, or words such as weeks, days, hours, minutes, seconds. Decimals are fine (1.5h, 2.25 days). Clock style follows the usual convention: two parts are h:mm, three are h:mm:ss, and four are d:hh:mm:ss.
That convention trips people up with clip lengths. A video that is 3 minutes 42 seconds long should be typed 0:03:42 or 3m 42s. Typed as 3:42 it means 3 hours and 42 minutes. Inside a line you can also use brackets and operators, for example (8h - 30m) * 5 for five working days with a half-hour lunch.
How are overnight shifts and breaks counted?
In Hours worked mode an end time earlier than the start time is read as the next day. 22:00 to 06:00 is 8 hours, and with a 30-minute unpaid break the worked time is 7.5 hours. A shift of exactly 24 hours needs the same start and end time, which the sheet reads as a full day.
The clock mode is plain wall-clock arithmetic. If a daylight saving change happens inside the span, the actual elapsed time is an hour longer or shorter than the clock difference. For one-off countdowns use a countdown timer instead.
Why use Mavros
| Mavros | Typical upload sites | |
|---|---|---|
| Input style | Free text: 1h 30m, 1:30, 90m, 1.5h | Separate boxes for hours, minutes, seconds |
| Number of values | Unlimited lines with running totals | Two values at a time |
| Multiply and divide | Yes, by plain numbers | Rarely |
| Decimal hours | Shown for every result | Sometimes, often on a separate page |
| Weekly timesheet with breaks | Built in, overnight shifts included | Separate tool |
| Shareable link | Yes, the sum is kept in the URL | No |
Tips
- Set Bare numbers mean to minutes when you're adding a list like 45, 30, 20. Set it to hours for a list like 7.5, 8, 6.25.
- Use the running total table to find a typo. A line that jumps the total by 40 hours usually means 40 was read in hours.
- For payroll, copy the decimal hours, not the h:mm figure.
- A time divided by a time gives a plain number: 3h / 40m = 4.5 sessions.
Questions
How do I add up hours and minutes?
Type each time on its own line, such as 2h 15m, 1:45 and 50m. The tool converts everything to seconds, adds it, and shows 4:50:00 along with the decimal value of 4.83 hours.
How many hours is 7 hours 45 minutes in decimal?
It is 7.75 hours. Divide the minutes by 60 (45 ÷ 60 = 0.75) and add them to the whole hours. Writing it as 7.45 is a common payroll mistake that underpays 18 minutes.
How do I subtract time?
Start a line with a minus sign. For example, 8h 30m on one line and - 45m on the next gives 7:45:00. Negative totals are shown with a minus sign rather than wrapping around.
Why does 3:42 show as 3 hours 42 minutes?
Two-part clock times are read as h:mm, the same as a clock face. For minutes and seconds type 0:03:42 or 3m 42s instead.
How do I calculate hours worked between two times?
Use Hours worked mode. Enter the start time, end time and unpaid break for each shift. The tool subtracts the break, handles shifts that cross midnight and totals the week in h:mm and decimal hours.
What time will it be in 8 hours?
Use Clock time ± duration. Press Now, choose Add, type 8h and read the result with its weekday. If it crosses midnight, the tool shows +1 day.
Can I add more than 24 hours?
Yes. Totals are not capped, so 30 hours shows as 30:00:00 and also as 1d 6h. This matters for weekly totals and long projects.