Skip to content
OneKitly
Sign up · Sign in

Time duration calculator

Work out how much time passes between a start and an end time.

Related tools

All Dates & time tools →
Time zone converterConvert a time from one UTC offset to another.Screen time calculatorSee how much your daily screen time adds up to over a week and a year.Reading time calculatorEstimate how long a text takes to read from its word count.Speech time calculatorEstimate how long it takes to read a speech aloud from its word count.Daily Time Savings CalculatorSee how a few minutes saved each day compound into hours, work days and weeks over a year.Email Reply Time CalculatorA tongue-in-cheek guide to the ideal window to reply to an email, from sender, urgency, timing and your strategy.Military Time ConverterConvert between 12-hour and 24-hour military time in both directions, with the full 0000-2300 chart, how to say each time out loud and the NATO zone letters.Zombie survival time calculatorWhen the outbreak hits, how long would you last? Choose your location, shelter, weapon, fitness, group and supplies, and this apocalyptic calculator estimates your survival time in days and weeks — and awards you a survivor rank, from zombie chow to wasteland legend.

The Time duration calculator turns Start — hour, Start — minute, End — hour, End — minute into Hours, Minutes, Total minutes, instantly and for free. For instance, with Start — hour = 9, Start — minute = 0, End — hour = 17 and End — minute = 30 it returns Hours = 8, Minutes = 30 and Total minutes = 510.

How to use it

  1. Enter your values: Start — hour, Start — minute, End — hour, End — minute.
  2. Read the result instantly: Hours, Minutes, Total minutes.

Frequently asked questions

What does the Time duration calculator actually compute?

It takes Start — hour, Start — minute, End — hour and End — minute and derives Hours, Minutes and Total minutes from them. The calculation is live as you type, so the result updates on every change.

What information do I need to provide?

4 values: Start — hour, Start — minute, End — hour and End — minute. Nothing else is required — no account, no file upload.

Can you show a worked example?

With Start — hour = 9, Start — minute = 0, End — hour = 17 and End — minute = 30, the calculator returns Hours = 8, Minutes = 30 and Total minutes = 510. Those figures come from running this exact tool, so you can reproduce them by entering the same values.

What happens if I enter larger values?

It moves a lot. Using Start — hour = 18, Start — minute = 5, End — hour = 34 and End — minute = 60 instead, Hours goes from 8 to 16 — which is why it is worth testing a few scenarios rather than trusting a single figure.

What does it give for smaller values?

Scaled down to Start — hour = 5, Start — minute = 1, End — hour = 9 and End — minute = 15, Hours comes out at 4. The relationship is worth checking at both ends before you rely on a single result.

When would I actually use this?

Answering a scheduling question exactly: how many working days until a deadline, what date falls sixty days out, and what time that is for a colleague elsewhere.

What is the most common mistake?

Counting days by subtracting dates and forgetting whether the endpoints are included. Inclusive and exclusive counts differ by one, which is the difference between meeting a deadline and missing it.

What is the difference between the Time duration calculator and the Time zone converter?

This one returns Hours and Minutes; the Time zone converter returns Converted hour. That is the whole difference — open the one whose figure you need.

Is there a tool for the next step?

Screen time calculator is the closest one after this: See how much your daily screen time adds up to over a week and a year.

What else is worth having open alongside it?

Reading time calculator and Speech time calculator — they come up in the same task often enough to be worth a second tab.

Further reading

All guides →
How-toHow to Add and Subtract Time (Hours and Minutes)Add and subtract hours and minutes reliably. Learn to carry over 60, borrow when subtracting, and handle a result that crosses midnight into the next day.ExplainerReading and Writing Military Time0800 is not “eight o'clock” and not “08:00” — it is “zero eight hundred”, with a zone letter on the end. The four digits, the spoken form, midnight at 0000, the argument about 2400, and the reason 12-hour notation cannot settle noon.GuideThe Pomodoro Method: How Long to Work and How Long to RestTwenty-five and five come from Francesco Cirillo's method, not from a trial. What the research actually measured is task switching and the cost of getting back in — and the reason a fixed interval helps is not that 25 minutes is optimal. Plus what the planner really returns, including the long break it quietly leaves out.ExplainerWhat an Availability Percentage Actually AllowsThree nines sounds like a promise until you divide it into minutes. What 99.9 % buys per year, per month, per week and per day; why the measurement window matters far more than the extra nine; and the two different months this tool uses for the same slug.GuideHours Worked With Breaks: the Two Questions the Arithmetic Cannot AnswerEnd minus start minus break is the easy part. Whether a break is paid and whether it counts as working time are two different questions with different answers by country — plus rounding, where timesheets actually go wrong, and what the tool does with a shift that crosses midnight.ExplainerHow Daylight Saving Time Works: Spring Forward, Fall BackDaylight saving time shifts clocks an hour in spring and back in autumn. Learn spring-forward and fall-back, why one day is 23 hours and another 25, and how US and EU dates differ.