Time calculator
Addition and subtraction of hours, minutes and seconds
to see the result
Time addition and subtraction calculator
It would seem that what could be simpler than ordinary mathematics? Every day we count money in the store, estimate gas mileage, or measure the area of a room when renovating. To do this, we are accustomed to using the standard decimal system: ten millimeters in a centimeter, one hundred kopecks in a ruble. But when it comes to timing, our brains often start to falter.
The problem is that hours and minutes live according to their own, ancient Babylonian rules - in the sexagesimal system. There are exactly 60 minutes in one hour, and 60 seconds in a minute. Because of this, an ordinary desktop or telephone computing device becomes useless. If you try to subtract the time of 8 hours 50 minutes (17.15 - 8.50) from 17 hours 15 minutes, you will get a strange figure 8.65, which has nothing to do with reality.
Who needs to count hours and minutes and why?
Difficulties with counting intervals arise for people of various professions and hobbies every day. There are various useful online calculators on the Internet for finance and construction, but it is the tools for working with time that stand apart due to their specificity. Here are just a few examples when accurate calculations are indispensable:
- Freelancers and remote workers If you work on an hourly basis, you need to know exactly how much net time is spent on a project. For example, you started at 10:45, took a break from 13:20 to 14:10, and finished at 18:05. It is almost impossible to calculate the total in your head without making mistakes.
- Accountants and HR specialists. When preparing time sheets for employees working on a complex shift schedule, an error in the calculations can lead to underpayment or overpayment of wages.
- Travelers and logisticians If the train leaves at 23:45 and the journey takes 14 hours and 30 minutes, what time will it arrive? When crossing the day, manual counting often leads to confusion.
- AthletesRunners and swimmers constantly add up the intervals of their laps to find out their total training time.
How does our calculator work?
To save you the hassle of converting hours to minutes, adding them together, and then dividing them back by 60, we created this tool. It works instantly right in your browser. You simply enter the initial value and choose the action: add or subtract.
If you need more in-depth calculations (for example, converting epochs or calculating the difference between two specific dates in a calendar), you can use a specialized time calculator that takes into account leap years and the number of days in different months. Our tool is focused on fast and accurate arithmetic within a day.
Table: Cheat sheet for converting fractions of an hour into minutes
Very often, in work contracts or time sheets, time is written in decimal fractions. For example, “1.5 hours” is understandable, it’s an hour and a half or 1 hour 30 minutes. What is "1.8 hours"? To avoid confusion, keep this handy translation table for yourself:
| Decimal hour | Real time in minutes | Example in the report card |
|---|---|---|
| 0.1 hours | 6 minutes | 0.1 hour late |
| 0.25 hours (quarter) | 15 minutes | Break 0.25 hours |
| 0.5 hours (half) | 30 minutes | Lunch 0.5 h |
| 0.75 hours (three quarters) | 45 minutes | Meeting 0.75 hours |
| 0.8 hours | 48 minutes | Work 0.8 h |
The main rule for manual calculation
If you still don’t have the Internet at hand and you need to calculate the interval on paper, always remember the golden rule: “We take six, not ten.” When you subtract minutes by a column and you are missing units from the top, you borrow 1 hour from the adjacent column. But this hour turns not into 100 units (as in ordinary mathematics), but into 60 minutes.
Conclusion
Technologies are created to take over routine. Don't waste your intellectual resources on adding Babylonian sexagesimal numbers. Bookmark this page, use our free online tool and always manage your schedule down to the second!