What is a time calculator?
A time calculator adds and subtracts lengths of time written in hours, minutes and seconds. Ordinary calculators work in base 10, but time uses base 60 – 60 seconds make a minute and 60 minutes make an hour – so 1:45 + 0:30 is 2:15, not 2:75. This online time calculator handles the carrying and borrowing for you and shows the answer as h:mm:ss, in words, and as total hours, minutes and seconds. A third mode finds the duration between two clock times, including times that cross midnight.
How to use this time calculator
- Choose a mode: Add two durations, Subtract a duration, or Time between two clock times.
- For add or subtract, type the hours, minutes and seconds of each duration. You can leave a box at 0, and you can type large values such as 150 minutes – the calculator normalises them.
- For clock times, enter a start and end time. If the end time is earlier (for example 22:00 to 06:00), it is treated as the next day.
- Read the result as h:mm:ss, in days-hours-minutes-seconds, and as decimal hours for timesheets and billing.
Time calculator formula
The simplest way to calculate time is to convert everything to seconds, do the maths, then convert back:
Total seconds = hours × 3,600 + minutes × 60 + seconds
- Hours = floor(total seconds ÷ 3,600)
- Minutes = floor((total seconds mod 3,600) ÷ 60)
- Seconds = total seconds mod 60
- Decimal hours = total seconds ÷ 3,600
Worked example: adding time
Add 2 h 45 min 30 s and 1 h 30 min 45 s. In seconds: 9,930 + 5,445 = 15,375 seconds. 15,375 ÷ 3,600 = 4 hours with 975 seconds left; 975 ÷ 60 = 16 minutes with 15 seconds left. The answer is 4:16:15, or 4.2708 decimal hours. That is the default example in the calculator above.
Worked example: subtracting time
Subtract 1:30:45 from 2:45:30. 9,930 − 5,445 = 4,485 seconds = 1:14:45. By hand, you would borrow: 30 s − 45 s needs a minute borrowed, giving 90 − 45 = 45 s; then 44 − 30 = 14 min; then 2 − 1 = 1 h.
Time between two times (start and end time)
To find how long something lasted, subtract the start time from the end time. From 9:15 AM to 5:40 PM is 8 hours 25 minutes. When the period crosses midnight – a night shift from 10 PM to 6 AM, for example – add 24 hours to the end time first: 30:00 − 22:00 = 8 hours. The clock mode of this time calculator between two times does this automatically, so PM to AM spans work without extra steps.
For work shifts with a lunch break and a weekly total, the hours calculator is a better fit: it subtracts the break, handles overnight shifts and adds up a whole week of hours.
Converting minutes to hours and decimal hours
Payroll and billing often need decimal hours rather than hours and minutes. Divide minutes by 60: 15 minutes = 0.25 h, 30 minutes = 0.5 h, 45 minutes = 0.75 h. So 7 hours 45 minutes is 7.75 hours, and at ₹400 an hour that pays ₹3,100. Many firms round to the nearest quarter hour.
| Minutes | Decimal hours | Minutes | Decimal hours |
|---|---|---|---|
| 5 | 0.083 | 35 | 0.583 |
| 10 | 0.167 | 40 | 0.667 |
| 15 | 0.25 | 45 | 0.75 |
| 20 | 0.333 | 50 | 0.833 |
| 25 | 0.417 | 55 | 0.917 |
| 30 | 0.5 | 60 | 1.0 |
Everyday uses of a time calculator
- Study time – add up study sessions across a day or week to track hours for board exams, JEE, NEET or UPSC preparation.
- Running and workouts – add lap or split times, or subtract to find how much faster you ran this time.
- Video and audio – total the length of clips in an edit. For playback speed, divide the duration by the speed: a 1:30:00 lecture at 1.5x takes 1:00:00, and at 2x (x2) it takes 45 minutes.
- Cooking and travel – add legs of a journey, layovers and buffer time.
- Work – total hours on tasks for invoices, then multiply decimal hours by your rate to get pay.
Time with speed and distance
If you know distance and speed, time = distance ÷ speed. A 300 km trip at 60 km/h takes 5 hours; at 75 km/h it takes 4 hours. For all three variables, use the speed distance time calculator, then add stops here to get total travel time.
Multiplying and dividing time
To multiply a duration, multiply its seconds: 45 minutes × 5 days = 225 minutes = 3:45:00. To divide, divide the seconds: 10 hours ÷ 4 people = 2:30:00 each. You can also add the same duration several times in this calculator by adding the result to the next value.
How to calculate time in Excel
Excel stores time as a fraction of a day. Type durations as 2:45:30 and add them with =A1+A2. Format the cell as [h]:mm:ss so totals over 24 hours show correctly. For decimal hours, use =A1*24. For start and end times that cross midnight, use =MOD(B1-A1,1).
Time zones
This tool measures durations, not time zones. To convert between IST and other zones, remember India is UTC+5:30 with no daylight saving: 9:00 AM EST (UTC−5) is 7:30 PM IST, and during US daylight time (EDT, UTC−4) it is 6:30 PM IST. For date-based durations, such as how long it has been since an event, use the date calculator.
Time calculator between two dates
This tool works with clock times and durations inside a day or across midnight. For a time calculator between two dates, such as 10 March 8:00 AM to 13 March 2:30 PM, count the whole days first with the date calculator (3 days = 72 hours), then add the clock difference here (6 hours 30 minutes). The total is 78 hours 30 minutes.
Time calculator with date: from date to date
The same two-step method handles a span from one date to another: days × 24 gives hours, then add or subtract the leftover time of day. Use this time calculator by date to go from one date to another and plan travel, shipping or project deadlines.
Time calculator for a year, month or years, months and days
A common question is how many hours are in a year: 365 × 24 = 8,760 hours (8,784 in a leap year), so the monthly average in the time calculator is 730 hours. The yearly figure for a full-time job, which the hours calculator also gives, is 40 hours × 52 weeks = 2,080 hours. To count years, months and days between two dates, the date calculator suits better than this time calculator.
Time calculator: how many hours and how many minutes
Use "Time between two clock times" for a time calculator how many hours answer: 9:15 AM to 5:40 PM is 8 hours 25 minutes, or 8.42 decimal hours, or 505 minutes. The time calculator in minutes view is useful for billing and timesheets.
Time calculator quarter hour rounding
Many employers round to the nearest quarter hour (15 minutes). With a time calculator quarter hour rule, 8 hours 25 minutes rounds to 8 hours 30 minutes (8.5 hours), because 25 is closer to 30 than to 15.
Time calculator with milliseconds
The inputs go down to seconds. For a time calculator with milliseconds, convert the milliseconds part separately: 1 second = 1,000 ms, so 2.750 s + 1.400 s = 4.150 s. Lap times and video frame edits usually need this precision.
Time calculator for video playback speed
A time calculator for playback speed divides the length by the speed. A 60-minute video at 1.5x takes 40 minutes; at 2x it takes 30 minutes; at 1.25x it takes 48 minutes. This video time calculator trick also shows how much time you save on a lecture series.
Time calculator for running and study
As a time calculator for running, multiply pace by distance: 5 km at 6:00 per km is 30 minutes, and a 21.1 km half marathon at 5:30 per km is 1 hour 56 minutes 3 seconds. As a time calculator for study, add up your sessions (for example 2:45 + 1:30 + 0:50 = 5:05) to track weekly study hours.
Time calculator for different countries: US and India
Comparing times in different countries needs each place's offset from UTC. India (IST) is UTC+5:30 with no daylight saving. New York is 10 hours 30 minutes behind IST in winter (EST) and 9 hours 30 minutes behind in summer (EDT), so to compare US and India times, use the time calculator as a simple zone converter by adding or subtracting that offset.
Time calculator India: JCB and machine hire hours
In India, JCB and other machine hire is billed from the hour meter or the start and end clock time. As a time calculator for JCB work, enter the start and end time, subtract breaks, and multiply the decimal hours by the hourly rate. For example, 3 hours 40 minutes is 3.67 hours; at an illustrative ₹1,000 per hour the bill is about ₹3,667. For payroll-style totals with breaks, use the hours calculator.
Time calculator kaise kare (how to use it)
Time calculator kaise kare? Pick a mode, type hours, minutes and seconds (ghante, minute, second) for both times, and read the result. The calculator carries 60 seconds into a minute and 60 minutes into an hour for you.
Time calculator app and live use
You do not need a time calculator app: this page runs in any phone or desktop browser and keeps working offline once loaded. It is not a live clock, so for the current time check your device, then use the time calculator to add or subtract from it.
Frequently asked questions
How do I add hours and minutes?
Add the minutes and hours separately. If the minutes reach 60 or more, subtract 60 and carry 1 to the hours. For example 1:45 + 2:30 = 3:75, which becomes 4:15. The time calculator does the carrying for you.
How do I subtract time?
Convert both times to seconds, subtract, then convert back to hours, minutes and seconds. For 2:45:30 − 1:30:45 the answer is 1:14:45.
How do I calculate the time between two times?
Subtract the start time from the end time. If the end is earlier than the start, add 24 hours first. From 9:15 to 17:40 is 8 hours 25 minutes.
How do I convert minutes to decimal hours?
Divide the minutes by 60. 45 minutes is 0.75 hours, so 7 hours 45 minutes is 7.75 hours.
Is there a time calculator that works with seconds?
Yes, this one. Enter hours, minutes and seconds for each duration and the result is shown to the second.
What is 1.5x of a 60 minute video?
At 1.5x playback a 60 minute video takes 60 ÷ 1.5 = 40 minutes. Divide the duration by the playback speed.
How do I add time in Excel?
Enter times as h:mm:ss, add them with a normal formula and format the total cell as [h]:mm:ss so it can go beyond 24 hours.
How do I calculate time between two dates?
Count full days between the dates and multiply by 24, then add the difference between the clock times. For example, 3 days and 6 hours 30 minutes is 78.5 hours.
How long is a 60 minute video at 1.5x speed?
Divide the length by the speed: 60 ÷ 1.5 = 40 minutes. At 2x it is 30 minutes.
What is the time difference between the US and India?
India is UTC+5:30. New York is 10 hours 30 minutes behind India in winter and 9 hours 30 minutes behind during US daylight saving time.
Last updated 2026-09-18