# Time Calculator Cardamon

> A free time-duration calculator. Type a natural expression such as "5h 30m + 2h 15m" or "2 days - 4h" and get the result instantly. The same calculation engine powers the Android and iOS apps, so results match across web and mobile.

## Facts
- Maker: Cardamon (contact: support@cardamon.org)
- Author & founder: Dmitrii Kargashin, solo founder of Cardamon Inc and the developer of Time Calculator (https://www.linkedin.com/in/dmitriy-kargashin)
- Rating: 4.6/5 from 391 ratings on Google Play
- Units: years, months, weeks, days, hours, minutes, seconds, milliseconds
- Operators (web, extension, any keyboard): + - * / (multiply and divide by a plain number only); every number needs a unit. The mobile keypad also offers × and ÷ keys.
- Reference: 1 day = 24 hours = 1,440 minutes = 86,400 seconds; 1 week = 7 days; 1 hour = 60 minutes; 1 minute = 60 seconds = 60,000 ms; 1 second = 1,000 ms
- Pricing: web is free (ad-supported); Android is free with no ads; iOS unlocks the full app with a Pro purchase

## Pages
- [Time Calculator (home)](https://www.timecalculator.app/): the web calculator, how it works, unit conversions, FAQ, and reviews
- [Guides](https://www.timecalculator.app/guides): step-by-step how-to guides for common time-math jobs
- [How do I add up hours and minutes?](https://www.timecalculator.app/guides/add-hours-and-minutes): Add up hours and minutes in one line. Type each duration like 8h 15m, join them with +, and pick a format. Free time calculator for timesheets, web and apps.
- [How do you calculate hours worked between two times?](https://www.timecalculator.app/guides/hours-worked-between-two-times): Calculate hours worked between two clock times. Write each time as hours and minutes from midnight, then subtract: 17h 45m - 9h 15m gives 8 Hours 30 Minutes.
- [How do I add and subtract time durations across units?](https://www.timecalculator.app/guides/add-and-subtract-time): Add and subtract time across hours, minutes, days, and weeks in one line. Type "2 days - 4h" and read the result in any format. Free, no conversion needed.
- [How do I total the hours on a weekly timesheet?](https://www.timecalculator.app/guides/timesheet-total-hours): Add up your weekly timesheet or time card hours in seconds. Type each day as hours and minutes, hit plus, and get a clean Hour Minute total. Free, in your browser.
- [How do I multiply or split a time duration?](https://www.timecalculator.app/guides/multiply-and-divide-time): Multiply or split a time duration in seconds. Type "8h 15m × 3" to repeat a block or "1 day ÷ 4" to divide it evenly. Free, right in your browser.
- [How do I convert between time units like minutes to seconds or hours to minutes?](https://www.timecalculator.app/guides/convert-time-units): Convert minutes to seconds, hours to minutes, seconds to hours, and milliseconds with a free time calculator. Type the duration, pick an output format, done.
- [Convert Time to Decimal Hours](https://www.timecalculator.app/guides/convert-time-to-decimal): Convert hours and minutes to decimal hours for payroll. See why 8h 15m = 8.25, the 15/30/45 rule, and how to handle repeating decimals like 8.3333333.
- [How to Calculate the Time Between Two Times](https://www.timecalculator.app/guides/time-between-two-times): Find the time between two times by writing each clock time as a duration from midnight, then subtracting. Examples for parking, ovens, study blocks, and flights.
- [Add Up Video and Audio Lengths (mm:ss and Milliseconds)](https://www.timecalculator.app/guides/add-video-audio-lengths): Total clip and track lengths in minutes and seconds, roll past an hour, and work in milliseconds. A free mm:ss calculator built for video editors and audio work.
- [Billable Hours Calculator](https://www.timecalculator.app/guides/billable-hours): Add up billable time across client sessions and convert the total to decimal hours for invoicing. Sum durations, multiply repeated tasks, and get a clean decimal.
- [How do I use a time card calculator to total payable hours?](https://www.timecalculator.app/guides/time-card-calculator): Free time card calculator: turn clock-in and clock-out punches into payable hours. Subtract 30m breaks, total the week, and convert to decimal for payroll.
- [Work Hours Calculator: How Many Hours Did I Work?](https://www.timecalculator.app/guides/work-hours-calculator): Free work hours calculator: type each shift like 8h 15m + 7h 45m + 8h, subtract breaks, and read the total as hours and minutes or decimal hours for payroll.
- [Overtime Calculator: Hours Over the 40-Hour Week](https://www.timecalculator.app/guides/overtime-calculator): Free overtime calculator: subtract the 40-hour week from your total, like 43h 45m - 40h = 3 Hours 45 Minutes, then read it as decimal hours for 1.5x pay.
- [How do I subtract lunch break from work hours?](https://www.timecalculator.app/guides/subtract-breaks-from-work-hours): Subtract lunch break from work hours in one line: 9h - 45m gives 8 Hours 15 Minutes. Chain minus signs to deduct every unpaid break and total the week.
- [Time unit converter](https://www.timecalculator.app/convert): single-pair conversions, each with a worked example and a reference table
- [Minutes to Hours](https://www.timecalculator.app/convert/minutes-to-hours): How many hours is 90 minutes? Divide the number of minutes by 60: 90 minutes ÷ 60 = 1.5 hours, and 240 minutes ÷ 60 = 4 hours.
- [Hours to Minutes](https://www.timecalculator.app/convert/hours-to-minutes): How many minutes is 2 hours? Multiply the number of hours by 60 to get total minutes: 3.25 hours x 60 = 195 minutes.
- [Seconds to Minutes](https://www.timecalculator.app/convert/seconds-to-minutes): How many minutes is 300 seconds? Divide the seconds by 60: 450 seconds / 60 = 7.5 minutes, which is 7 minutes and 30 seconds.
- [Minutes to Seconds](https://www.timecalculator.app/convert/minutes-to-seconds): How many seconds is 5 minutes? Multiply the minutes by 60 to get seconds: 7 minutes x 60 = 420 seconds, and a fractional value like 2.5 minutes x 60 = 150 seconds.
- [Days to Hours](https://www.timecalculator.app/convert/days-to-hours): How many hours is 3 days? Multiply the number of days by 24 to get hours, so 5 days × 24 = 120 hours.
- [Hours to Days](https://www.timecalculator.app/convert/hours-to-days): How many days is 60 hours? Divide the number of hours by 24: 90 hours divided by 24 equals 3.75, which reads as 3 days and 18 hours (the 0.75 of a day is 0.75 times 24, or 18 hours).
- [Weeks to Days](https://www.timecalculator.app/convert/weeks-to-days): How many days is 2 weeks? Multiply the number of weeks by 7 to get days: 4 weeks × 7 = 28 days, and 2.5 weeks × 7 = 17.5 days.
- [Milliseconds to Seconds](https://www.timecalculator.app/convert/milliseconds-to-seconds): How many seconds is 2500 milliseconds? Divide the number of milliseconds by 1000 to get seconds: 2500 ms ÷ 1000 = 2.5 seconds, and 9000 ms ÷ 1000 = 9 seconds.
- [Seconds to Milliseconds](https://www.timecalculator.app/convert/seconds-to-milliseconds): How many milliseconds is 3 seconds? Multiply the number of seconds by 1000 to get milliseconds: 7 seconds × 1000 = 7000 ms.
- [Seconds to Hours](https://www.timecalculator.app/convert/seconds-to-hours): How many hours is 7200 seconds? Divide the number of seconds by 3600: 7200 seconds ÷ 3600 = 2 hours, and 5400 seconds ÷ 3600 = 1.5 hours.
- [Hours to Seconds](https://www.timecalculator.app/convert/hours-to-seconds): How many seconds is 2 hours? Multiply the number of hours by 3600 to get total seconds: 2 hours × 3600 = 7200 seconds, and 2.5 hours × 3600 = 9000 seconds.
- [Days to Weeks](https://www.timecalculator.app/convert/days-to-weeks): How many weeks is 14 days? Divide the number of days by 7 to get weeks: 14 days ÷ 7 = 2 weeks, and 3.5 days ÷ 7 = 0.5 weeks.
- [Years to Days](https://www.timecalculator.app/convert/years-to-days): How many days is 2 years? Multiply the number of years by 365 to get days: 2 years × 365 = 730 days, and 0.5 years × 365 = 182.5 days.
- [Days to Years](https://www.timecalculator.app/convert/days-to-years): How many years is 730 days? Divide the number of days by 365 to get years: 730 days ÷ 365 = 2 years, and 182.5 days ÷ 365 = 0.5 years.
- [Reviews](https://www.timecalculator.app/reviews): real Google Play reviews (4.6 stars, 391 ratings)
- [Support](https://www.timecalculator.app/support): help, FAQ, and contact (support@cardamon.org)
- [Mobile app](https://www.timecalculator.app/app): the Android and iOS app, its screens and features
- [What's new](https://www.timecalculator.app/whats-new): app release notes
- [Dmitrii Kargashin](https://www.timecalculator.app/dmitrii-kargashin): the maker — solo founder of Cardamon Inc and the developer behind Time Calculator
- [Privacy policy](https://www.cardamon.org/products/time-calculator/privacy-policy-time-calculator)

## Apps
- Google Play: https://play.google.com/store/apps/details?id=com.dmitriykargashin.cardamontimecalculator
- Apple App Store: https://apps.apple.com/app/id6789162864
- Chrome extension (side panel + address-bar keyword "tc"): https://chromewebstore.google.com/detail/time-calculator-cardamon/apgmodigokbblokbgfokpobmlcmijjpl

## For LLMs and coding agents
- https://www.timecalculator.app/llms.txt — this curated index of pages with short descriptions.
- https://www.timecalculator.app/llms-full.txt — every page's content concatenated into one markdown file for one-shot ingestion.