Time Calculator

Add or subtract times to calculate total time or time difference

Free online time calculator. Add two times together to get the total time, or subtract one time from another to get the time difference. Perfect for work hours management, project time tracking, video editing, training logs and more. Browser-based, privacy protected.

How to Use

Calculate time in 3 steps:

Step 1: Select Calculation Type
Use the 'Time Addition' section to add times, or the 'Time Subtraction' section to subtract times
Step 2: Enter Times
Enter each time in hours, minutes, and seconds format. Enter both Time 1 and Time 2
Step 3: Calculate
Click the 'Calculate' button and the result will be displayed instantly in HH:MM:SS format

All calculations are performed in your browser. Your time data is not sent to any server.

Time Calculation Tool

Time Addition

Time 1: 例: 1:30:45 または 01:30:45

Time 2: 例: 2:15:30 または 02:15:30

Result

--:--:--

Time Subtraction

Time 1: 例: 5:30:00 または 05:30:00

Time 2: 例: 2:15:30 または 02:15:30

Result

--:--:--

Practical Use Cases

Time calculator is useful in various scenarios:

1. Work Hours Management

Calculate actual working hours from clock-in and clock-out times. Add multiple work periods (morning + afternoon shifts) to get total daily working hours. Subtract break times to determine actual productive hours. Example: 09:00-12:00 + 13:00-18:00 = 8 hours of work.

2. Project Time Tracking

Add up time spent on each task to calculate total project hours. Combine multiple work sessions to understand overall project duration. Calculate the difference between estimated and actual time for progress management and future planning.

3. Video Editing & Production

Add lengths of multiple video clips to calculate total video duration. Subtract current duration from target duration to determine how much additional footage is needed. Support timecode calculations for precise editing work.

4. Training & Exercise Logs

Add workout times for different activities (running, cycling, swimming) to calculate total daily training time. Compare goal time with actual time to adjust training plans. Track weekly and monthly cumulative training hours.

5. Travel Planning & Transit Time

Add transit times for multiple segments to calculate total travel duration. Subtract departure time from arrival time to determine stay duration. Account for connection times and waiting periods for accurate itinerary planning.

What is Time Calculation?

Time calculation is the process of adding or subtracting two or more time values to find total time or time difference. It's a fundamental calculation needed in various daily life and business scenarios.

How Time Addition Works

Time addition combines two times to find the total time. Example: 02:30:15 + 01:45:30 = 04:15:45. Hours, minutes, and seconds are added separately, with carries handled using 60 seconds = 1 minute and 60 minutes = 1 hour. Widely used for calculating total work hours, project time aggregation, and video clip duration.

How Time Subtraction Works

Time subtraction finds the time difference by subtracting one time from another. Example: 05:30:00 - 02:15:30 = 03:14:30. Used to calculate elapsed time between start and end times, or to find the difference between target and actual times. Supports negative values for reverse time differences.

Browser-Based Privacy

This time calculator uses JavaScript to perform calculations entirely in your browser. Your time data is never sent to any server, ensuring complete privacy protection. Works offline with no communication errors. Safe for calculating sensitive information like work hours.

Frequently Asked Questions

Can I calculate times exceeding 24 hours?

Yes, you can calculate times exceeding 24 hours without any issues. For example, 30 hours + 10 hours = 40 hours is fully supported. Results will be displayed as 40:00:00. Perfect for calculating long-duration projects or multi-day work hours.

Will negative time (minus) be displayed?

Yes, when subtracting times where Time 1 is less than Time 2, the result will be displayed as a negative value. Example: 02:00:00 - 05:00:00 = -03:00:00. This clearly shows delay time or time shortage. Useful for comparing planned vs actual time in project management.

Can I enter only minutes or seconds?

Yes, you can enter any combination of hours, minutes, and seconds. For example, '0 hours 30 minutes 0 seconds' is calculated as '30 minutes', and '0 hours 0 minutes 45 seconds' as '45 seconds'. Unspecified units are treated as 0, allowing flexible usage.

What happens if I enter values over 60 for minutes or seconds?

Values over 60 are calculated correctly. For example, '0 hours 90 minutes 0 seconds' is automatically calculated as '1 hour 30 minutes 0 seconds'. However, for accuracy, we recommend entering values in appropriate units for hours, minutes, and seconds.

Can I subtract break time from work hours?

Yes, use the time subtraction feature. For example, subtract 1 hour of break time from 9 hours of work time to get 8 hours of actual working time. If there are multiple break periods, first add them together, then subtract the total from work time.

Can I enter decimal times (e.g., 2.5 hours)?

This tool is designed for hours, minutes, and seconds input. For decimal format (2.5 hours), please convert to sexagesimal first. Example: 2.5 hours = 2 hours 30 minutes 0 seconds. This provides more intuitive input and clearer result display.

Can I add more than two times at once?

Currently, the tool supports adding or subtracting two times. To add three or more times, first calculate the first two, then add the result to the next time. This step-by-step approach ensures accurate complex time calculations.

Can I copy the calculation result?

Yes, the result is displayed as text, making it easy to copy. Click the result to select it, then press Ctrl+C (Mac: Cmd+C) to copy. You can paste it into Excel, Notepad, or other applications for recording and management.