Time Calculator Hours Minutes Seconds
Add and subtract time in hh:mm:ss format with a live running total
Time Entry Shortcuts
| 5.. | 5 hours 0 min 0 sec → 05:00:00 |
| 5.22. | 5 hours 22 min 0 sec → 05:22:00 |
| 5.22.10 | 5 hours 22 min 10 sec → 05:22:10 |
| .22. | 0 hours 22 min 0 sec → 00:22:00 |
| .22.15 | 0 hours 22 min 15 sec → 00:22:15 |
| ..5 | 0 hours 0 min 5 sec → 00:00:05 |
| -1.30. | Subtract 1 hour 30 min → −01:30:00 |
| 1:30:00 | Standard colon format → 01:30:00 |
Time Unit Conversion Reference
| Unit | Seconds | Minutes | Hours | Days |
|---|---|---|---|---|
| 1 minute | 60 | 1 | 0.01667 | 0.000694 |
| 1 hour | 3,600 | 60 | 1 | 0.04167 |
| 1 day | 86,400 | 1,440 | 24 | 1 |
| 1 week | 604,800 | 10,080 | 168 | 7 |
| 30 min | 1,800 | 30 | 0.5 | 0.020833 |
| 90 min | 5,400 | 90 | 1.5 | 0.0625 |
| 45 min | 2,700 | 45 | 0.75 | 0.03125 |
How to Add and Subtract Time in HH:MM:SS
Adding and subtracting time in hh:mm:ss format requires carrying and borrowing between units, since each unit has a base of 60 (not 10). This time calculator handles all the arithmetic automatically and maintains a running total like a tape-style adding machine.
Manual Addition Method
- Add the seconds together. If the result is 60 or more, subtract 60 and carry 1 to minutes.
- Add the minutes together plus any carry. If the result is 60 or more, subtract 60 and carry 1 to hours.
- Add the hours together plus any carry.
Example: 1:45:50 + 0:30:25. Seconds: 50 + 25 = 75 = 15 carry 1. Minutes: 45 + 30 + 1 = 76 = 16 carry 1. Hours: 1 + 0 + 1 = 2. Result: 2:16:15.
Manual Subtraction Method
Convert both times to total seconds, subtract, and convert back. Example: 2:30:00 minus 1:45:30. First: 2:30:00 = 9,000 seconds. Second: 1:45:30 = 6,330 seconds. Difference: 9,000 minus 6,330 = 2,670 seconds = 0:44:30.
Converting Between Time Formats
Time format conversion is common in payroll, project tracking, and scheduling. The hh:mm:ss format and decimal hours are the two most frequently used representations.
HH:MM:SS to Decimal Hours
Divide the minutes by 60 and the seconds by 3600, then add both to the hours. For 1 hour 30 minutes: 1 + (30 ÷ 60) + (0 ÷ 3600) = 1.5 decimal hours. For 2 hours 15 minutes 36 seconds: 2 + (15 ÷ 60) + (36 ÷ 3600) = 2 + 0.25 + 0.01 = 2.26 decimal hours.
Decimal Hours to HH:MM:SS
Take the whole number as hours. Multiply the decimal part by 60 to get minutes; take the whole number as minutes. Multiply any remaining decimal by 60 to get seconds. For 2.75 hours: 2 hours, 0.75 × 60 = 45 minutes, 0 seconds = 2:45:00.
Common Uses for a Time Calculator
A time calculator is used wherever duration needs to be totaled, compared, or converted. Common applications span several fields.
Payroll and Timesheets
Employees and employers use time calculators to total daily and weekly work hours accurately. Adding multiple daily shifts and converting the total to decimal hours ensures correct pay calculations.
Sports and Fitness Timing
Athletes and coaches use time calculators to total lap times, split times, and training session durations. Race officials use them to subtract start times from finish times when timing equipment is manual.
Video and Audio Production
Editors use hh:mm:ss format to manage timecode, calculate clip durations, and total project runtime. Adding segment lengths to find total runtime is a daily task in post-production workflows.
Frequently Asked Questions
To add hours, minutes, and seconds: first add all seconds, then divide by 60 to get carry-over minutes; then add all minutes plus carry-over, divide by 60 to get carry-over hours; then add all hours plus carry-over. For example, 1:45:50 plus 0:30:25 equals 2:16:15.
To subtract time in HH:MM:SS, convert both times to total seconds, subtract the smaller from the larger, then convert back. For example, 2:30:00 minus 1:45:30 equals 0:44:30 (9000 seconds minus 6330 seconds = 2670 seconds = 44 minutes 30 seconds).
To convert HH:MM:SS to decimal hours, divide the minutes by 60 and the seconds by 3600, then add these to the hours. For example, 2:30:00 equals 2 + 30/60 + 0/3600 = 2.5 hours. One hour and 15 minutes equals 1.25 decimal hours.
HH:MM:SS is a standard duration format where HH represents hours, MM represents minutes (00 to 59), and SS represents seconds (00 to 59). It is used in timesheets, video duration, sports timing, and scientific measurement. Hours can exceed 24 when representing total durations longer than one day.
There are 3,600 seconds in one hour. This is because one hour contains 60 minutes and each minute contains 60 seconds, so 60 times 60 equals 3,600 seconds per hour.