How do I add hours and minutes?

Type each time on its own line and read the total. For example 3:45, 2:30 and 1:50 add up to 8:05:00 (8 hours 5 minutes, which is 8.0833 decimal hours or 485 minutes). By hand: add the minutes (45 + 30 + 50 = 125), carry every 60 into the hours (125 minutes is 2 hours 5 minutes), then add the hours (3 + 2 + 1 + 2 = 8).

How do I add minutes and seconds?

Use units so the calculator knows which number is which: 3m 45s, 2m 50s and 4m 15s add up to 0:10:50, which is 10 minutes 50 seconds (10.83 minutes, 650 seconds). A form like 3:45 is read as hours and minutes (3 hours 45 minutes), so write 3m 45s for minutes and seconds.

How do I subtract time?

Put a minus sign in front of the time to take away. 2:30:15 plus 1h 45m 50s minus 0:20:00 is 3:56:05. If you subtract more than you added the result is negative and is shown with a minus sign, for example 0:20:00 minus 0:45:00 is -0:25:00.

How do I convert minutes to decimal hours?

Divide the minutes by 60: 15 minutes is 0.25 hours, 30 minutes is 0.5, 45 minutes is 0.75, 20 minutes is 0.33 (0.3333 rounded). To convert hours and minutes, divide only the minutes by 60 and add the whole hours: 7 hours 45 minutes is 7 + 45/60 = 7.75. The decimal hours line in the results does this for any total, and the reference table below lists every 5 minutes.

What time will it be in 8 hours (or any amount of time)?

Enter the clock time you start from (for example 9:00 AM) in "Start from a clock time" and the amount to add (8h). The answer is 5:00 PM (17:00). If the sum passes midnight the result says how many days later it is: 10:30 PM plus 5 hours 45 minutes is 4:15 AM, 1 day later. Subtract with a minus sign: 1:00 AM minus 2 hours is 11:00 PM, 1 day earlier. Only the time you type is used; the calculator does not read your clock.

How do I calculate the time between two times?

Switch to "Hours between a start and an end time" here, or use the Time Duration calculator if the two times fall on different dates. 9:00 AM to 5:00 PM is 8 hours, and 8:00 AM to 5:00 PM is 9 hours. If the end is earlier than the start the calculator assumes the end is on the next day, so 10:00 PM to 6:00 AM is 8 hours. Enter an unpaid break in minutes and it is taken off.

How many hours is 9 to 5, or 8 am to 5 pm?

9 to 5 is 8 hours with no break, or 7.5 hours (7:30) with a 30-minute unpaid lunch. 8 am to 5 pm is 9 hours, or 8 hours with a 1-hour unpaid lunch, and 7.5 hours is 7 hours 30 minutes.

Can the total be more than 24 hours?

Yes. Hours are not capped at 24: 14:30 plus 11:45 is 26:15:00, shown as 1 day 2 hr 15 min. Only the optional "resulting clock time" is wrapped to a time of day.

Does it accept 12-hour and 24-hour (military) time?

For clock times, yes: 9:00 AM, 9 pm and 21:30 all work (the optional start clock time also takes 24:00 for the end of the day), and 12:00 AM is midnight while 12:00 PM is noon. The start and end times in the between-two-times mode take 12-hour or 24-hour times such as 9:00 AM or 17:30. Lengths of time are not clock times, so they are written as h:mm, h:mm:ss or with units. In h:mm form the minutes and seconds must be 00 to 59; use units for larger numbers, such as 125m.

Where is the time card or timesheet calculator?

Use the Time Card calculator to total a whole week of clock-in and clock-out times with breaks, overnight shifts, rounding to 5, 6, 10 or 15 minutes, overtime and an estimated pay.

Time Calculator

Add and subtract hours, minutes, seconds and days. Get the total as h:mm:ss, decimal hours and minutes, or the clock time you land on. Free, no sign-up.

✓ Tested formula & cited sources Checked against independent sources · Oct 16, 2026 Private: runs in your browser

What do you want to calculate?

Times to add or subtract

One time per line, or in one line like 1h 30m + 45m - 10m. Use h:mm, h:mm:ss or units (1d 2h 3m 4s, 90m). A time with no sign is added; start a line with - to subtract it.

Start from a clock time (optional)

Leave blank to just total the times. Enter a time of day such as 9:00 AM or 21:30 to see the clock time you land on, for example 9:00 AM plus 8 hours.

Results

Total (H:MM:SS)

3:56:05

Days, hours, minutes, seconds: 3 hr 56 min 5 sec
Decimal hours: 3.9347
Total minutes: 236.08
Total seconds: 14165
Times counted: 3

The formula

Total seconds = Σ ± (hours × 3600 + minutes × 60 + seconds) | Decimal hours = total seconds ÷ 3600 | Between two clock times: End − Start − Break

T: Total time
C: Resulting clock time
GP: Gross pay (between-two-times mode)

Worked example — Times to add or subtract 2:30:15 + 1h 45m 50s - 0:20:00, Break Deduction (minutes) 30, Hourly Rate ($) 25.00

Total (H:MM:SS) = 3:56:05

Full explanation ↓

How Time Calculator Works

Total seconds = Σ ± (hours × 3600 + minutes × 60 + seconds) | Decimal hours = total seconds ÷ 3600 | Between two clock times: End − Start − Break

To add or subtract time, convert every value to seconds (hours × 3600 + minutes × 60 + seconds, days × 86,400), add the values you want to add, take away the ones you want to subtract, then turn the total back into hours, minutes and seconds. Decimal hours are the total seconds divided by 3,600. If you also enter a start clock time, the total is added to it and wrapped around a 24-hour day, so 10:30 PM plus 5 hours 45 minutes lands on 4:15 AM the next day.

The second mode finds the time between a start and an end time of day (it assumes the end is the next day when it is earlier), takes off an unpaid break, and can multiply by an hourly rate.

T: Total time — The signed sum of everything you entered, in seconds, shown as H:MM:SS, as days/hours/minutes/seconds, and as decimal hours, total minutes and total seconds. It can be longer than 24 hours or negative.
C: Resulting clock time — Only when you enter a start clock time: (start + T) wrapped around 24 hours, with a note of how many days later or earlier it falls.
GP: Gross pay (between-two-times mode) — Decimal hours × hourly rate, rounded to the cent. An estimate before tax, shown only when a rate is entered.

Adding times: add the minutes, carry every 60 into the hours, then add the hours.

Worked Examples

Three tasks took 3 hours 45 minutes, 2 hours 30 minutes and 1 hour 50 minutes, and you want the total for your timesheet.

mode = addsub · terms = 3:45 + 2:30 + 1:50 · baseTime =

8:05:00 (8.0833 decimal hours, 485 minutes)

The minutes add to 125, which carries 2 hours into the hours column, leaving 5 minutes: 3 + 2 + 1 + 2 = 8 hours 5 minutes. Divide 485 minutes by 60 for 8.0833 decimal hours.

You start a night task at 10:30 PM and it will take 5 hours 45 minutes. What time does it finish?

mode = addsub · terms = 5:45 · baseTime = 10:30 PM

4:15 AM (04:15), 1 day later

10:30 PM is 22:30. 22:30 + 5:45 = 28:15, and 28:15 − 24:00 = 4:15, so the task ends at 4:15 AM the next calendar day.

Three laps took 3 minutes 45 seconds, 2 minutes 50 seconds and 4 minutes 15 seconds. How long was the total?

mode = addsub · terms = 3m 45s + 2m 50s + 4m 15s · baseTime =

0:10:50 (10.83 minutes, 650 seconds)

225 + 170 + 255 = 650 seconds, and 650 seconds is 10 minutes 50 seconds. Entering the laps as 3m 45s (not 3:45) tells the calculator they are minutes and seconds.

Carlos works as a barista at a cafe in Austin, Texas. His shift runs from 7:00 AM to 3:30 PM with an unpaid 30-minute lunch break, at $18.50 an hour. He wants to verify his hours and expected pay for the day.

mode = between · startTime = 7:00 AM · endTime = 3:30 PM · breakMinutes = 30 · hourlyRate = 18.50

8 hours 0 minutes (8.00 decimal hours); Gross pay: $148.00

7:00 AM to 3:30 PM is 8.5 hours, minus the 30-minute break is 8.0 hours. Gross pay is 8.0 hours × $18.50 = $148.00. The decimal figure (8.00) is what payroll uses, the hours-and-minutes figure is what a paper timesheet shows.

Maria is a night security guard in Chicago. She works from 10:00 PM to 6:00 AM with a 45-minute unpaid break and earns $22.00 an hour.

mode = between · startTime = 10:00 PM · endTime = 6:00 AM · breakMinutes = 45 · hourlyRate = 22.00

7 hours 15 minutes (7.25 decimal hours); Gross pay: $159.50

The end time is earlier than the start time, so the shift crosses midnight: 8 hours minus the 45-minute break is 7.25 hours. 7.25 × $22.00 = $159.50.

David is a freelance designer billing a client. He started at 9:15 AM and finished at 4:45 PM with no break, at $75 an hour.

mode = between · startTime = 9:15 AM · endTime = 4:45 PM · breakMinutes = 0 · hourlyRate = 75

7 hours 30 minutes (7.50 decimal hours); Gross pay: $562.50

9:15 AM to 4:45 PM is exactly 7.5 hours, so the invoice is 7.5 × $75 = $562.50.

Understanding the Result

A time calculator does arithmetic in base 60 for you. Adding 3 hours 45 minutes and 2 hours 30 minutes by hand means carrying: 45 + 30 = 75 minutes, which is 1 hour 15 minutes, so the total is 7 hours 15 minutes. This calculator converts everything to seconds first, so there is no carrying to get wrong, and it keeps going past 24 hours (26:15:00 is 1 day 2 hours 15 minutes).

It handles three everyday jobs. First, totalling a list of durations, such as the lengths of shifts, tasks, laps or videos. Second, adding or subtracting a length of time from a time of day, such as "what time is it 8 hours after 9:00 AM". Third, finding the hours between two times of day, including shifts that cross midnight. For a full week of clock-in and clock-out times with rounding and overtime use the Time Card calculator, and for a span that crosses dates use the Time Duration calculator.

All of it is plain clock arithmetic, so the answer does not depend on today's date, your time zone or daylight saving time.

How to Use

Type each time on its own line (or in one line, like 1h 30m + 45m - 10m). Use h:mm (1:30), h:mm:ss (1:30:15) or units (2h 15m, 90m, 45s, 1d 3h).
A time with no sign is added. Put - in front of a time to subtract it.
Optional: enter a clock time such as 9:00 AM in "Start from a clock time" to see what time you land on after adding or subtracting.
Read the total as H:MM:SS, as days/hours/minutes/seconds, or as decimal hours, total minutes and total seconds. The table shows the running total after each line.
To find the hours between a start and an end time, switch to "Hours between a start and an end time" (overnight shifts, an unpaid break and an hourly rate are supported).

Quick Reference

5 minutes	0.08 hours
10 minutes	0.17 hours
15 minutes	0.25 hours
20 minutes	0.33 hours
25 minutes	0.42 hours
30 minutes	0.50 hours
35 minutes	0.58 hours
40 minutes	0.67 hours
45 minutes	0.75 hours
50 minutes	0.83 hours
55 minutes	0.92 hours
60 minutes	1.00 hours

1 day	24 hours = 1,440 minutes = 86,400 seconds
9 to 5	8 hours (7.5 with a 30-minute lunch)
8 am to 5 pm	9 hours (8 with a 1-hour lunch)
7.5 hours	7 hours 30 minutes
12:00 AM / 12:00 PM	midnight / noon

Frequently Asked Questions

How do I add hours and minutes?: Type each time on its own line and read the total. For example 3:45, 2:30 and 1:50 add up to 8:05:00 (8 hours 5 minutes, which is 8.0833 decimal hours or 485 minutes). By hand: add the minutes (45 + 30 + 50 = 125), carry every 60 into the hours (125 minutes is 2 hours 5 minutes), then add the hours (3 + 2 + 1 + 2 = 8).
How do I add minutes and seconds?: Use units so the calculator knows which number is which: 3m 45s, 2m 50s and 4m 15s add up to 0:10:50, which is 10 minutes 50 seconds (10.83 minutes, 650 seconds). A form like 3:45 is read as hours and minutes (3 hours 45 minutes), so write 3m 45s for minutes and seconds.
How do I subtract time?: Put a minus sign in front of the time to take away. 2:30:15 plus 1h 45m 50s minus 0:20:00 is 3:56:05. If you subtract more than you added the result is negative and is shown with a minus sign, for example 0:20:00 minus 0:45:00 is -0:25:00.
How do I convert minutes to decimal hours?: Divide the minutes by 60: 15 minutes is 0.25 hours, 30 minutes is 0.5, 45 minutes is 0.75, 20 minutes is 0.33 (0.3333 rounded). To convert hours and minutes, divide only the minutes by 60 and add the whole hours: 7 hours 45 minutes is 7 + 45/60 = 7.75. The decimal hours line in the results does this for any total, and the reference table below lists every 5 minutes.
What time will it be in 8 hours (or any amount of time)?: Enter the clock time you start from (for example 9:00 AM) in "Start from a clock time" and the amount to add (8h). The answer is 5:00 PM (17:00). If the sum passes midnight the result says how many days later it is: 10:30 PM plus 5 hours 45 minutes is 4:15 AM, 1 day later. Subtract with a minus sign: 1:00 AM minus 2 hours is 11:00 PM, 1 day earlier. Only the time you type is used; the calculator does not read your clock.
How do I calculate the time between two times?: Switch to "Hours between a start and an end time" here, or use the Time Duration calculator if the two times fall on different dates. 9:00 AM to 5:00 PM is 8 hours, and 8:00 AM to 5:00 PM is 9 hours. If the end is earlier than the start the calculator assumes the end is on the next day, so 10:00 PM to 6:00 AM is 8 hours. Enter an unpaid break in minutes and it is taken off.
How many hours is 9 to 5, or 8 am to 5 pm?: 9 to 5 is 8 hours with no break, or 7.5 hours (7:30) with a 30-minute unpaid lunch. 8 am to 5 pm is 9 hours, or 8 hours with a 1-hour unpaid lunch, and 7.5 hours is 7 hours 30 minutes.
Can the total be more than 24 hours?: Yes. Hours are not capped at 24: 14:30 plus 11:45 is 26:15:00, shown as 1 day 2 hr 15 min. Only the optional "resulting clock time" is wrapped to a time of day.
Does it accept 12-hour and 24-hour (military) time?: For clock times, yes: 9:00 AM, 9 pm and 21:30 all work (the optional start clock time also takes 24:00 for the end of the day), and 12:00 AM is midnight while 12:00 PM is noon. The start and end times in the between-two-times mode take 12-hour or 24-hour times such as 9:00 AM or 17:30. Lengths of time are not clock times, so they are written as h:mm, h:mm:ss or with units. In h:mm form the minutes and seconds must be 00 to 59; use units for larger numbers, such as 125m.
Where is the time card or timesheet calculator?: Use the Time Card calculator to total a whole week of clock-in and clock-out times with breaks, overnight shifts, rounding to 5, 6, 10 or 15 minutes, overtime and an estimated pay.

Pro Tips

→Write minutes and seconds with units (3m 45s). A bare 3:45 means 3 hours 45 minutes.
→Use units for big numbers: 125m is accepted and equals 2:05:00, while 1:125 is not a valid h:mm time.
→Paste a column of times straight in, one per line. A leading - subtracts that line, and the table shows the running total after each line so you can spot a typo.
→For payroll, copy the decimal hours (for example 7.75), not the H:MM:SS figure, and round the way your employer does.
→To find what time something ends, enter the start as a clock time and the length as a duration. To find how long something lasted, switch to the between-two-times mode.

Limitations to Know

•Lengths of time are entered as h:mm, h:mm:ss or with units. A bare number such as 45 is not guessed because it could be minutes or hours.
•The resulting clock time is plain 24-hour clock arithmetic. It does not know about time zones or daylight saving changes; use the Time Zone calculator to convert between zones.
•The between-two-times mode handles one shift of up to 24 hours, with identical start and end times counted as zero. For anything longer, or across dates, use the Time Duration calculator.
•Pay in the between-two-times mode is an estimate before tax and deductions, at one rate with no overtime; the Time Card calculator adds overtime.
•For critical payroll or billing, check the figures against your official timekeeping records.

Sources

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Cite this calculator

TheCalcUniverse. "Time Calculator: Add & Subtract Hours, Minutes, Seconds." TheCalcUniverse, 2026, https://thecalcuniverse.com/math/time-calculator/. Accessed October 25, 2026.

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