Time Calculator – Add & Subtract Hours, Minutes, Seconds Online

Calculate time durations with precision. Add or subtract hours, minutes, and seconds for scheduling, payroll, project tracking, and everyday time math. Free online time calculator with instant results.

What Is a Time Calculator?

A time calculator performs arithmetic on time values—adding durations together or subtracting one time from another. Unlike regular calculators that work with decimal numbers, time calculators properly handle the 60-minute hour and 60-second minute conversions.

Why Time Math Is Tricky

Time doesn't work in base-10:

60 seconds = 1 minute
60 minutes = 1 hour
24 hours = 1 day

Adding 45 minutes + 30 minutes = 1 hour 15 minutes, not 75 minutes. Our calculator handles these conversions automatically.

Features of Our Time Calculator

Feature	Description
Add Times	Sum multiple time durations together
Subtract Times	Find the difference between times
Multiple Units	Work with hours, minutes, and seconds
Instant Results	Calculate in real-time as you type
Copy Results	One-click copy to clipboard
Clean Format	Results shown as HH:MM:SS

How to Use This Tool

Adding Time

Enter your first time duration (hours, minutes, seconds)
Click "Add" to include additional time entries
Enter subsequent durations
View the total automatically calculated

Subtracting Time

Enter your starting time or duration
Select the subtract operation
Enter the time to subtract
View the remaining time

Common Use Cases

Payroll & Timesheets

Calculate total work hours across multiple shifts:

Monday: 8h 30m
Tuesday: 7h 45m
Wednesday: 9h 15m
Total: 25h 30m

Project Management

Track time spent on tasks and estimate remaining work:

Estimated: 40h 00m
Completed: 27h 45m
Remaining: 12h 15m

Video/Audio Editing

Calculate total runtime of clips:

Intro: 0:45
Main content: 12:30
Outro: 1:15
Total: 14:30

Exercise & Fitness

Sum workout session durations:

Running: 35:00
Stretching: 10:00
Cooldown: 5:00
Total: 50:00

Cooking & Recipes

Add cooking times for multi-step recipes when timing matters for coordination.

Travel Planning

Calculate flight durations with layovers, or estimate total trip time.

Time Calculation Examples

Operation	Input	Result
Add	2h 30m + 1h 45m	4h 15m
Add	0:45:30 + 0:30:45	1:16:15
Subtract	8h 00m - 5h 30m	2h 30m
Subtract	2:00:00 - 0:15:30	1:44:30

Frequently Asked Questions

What time formats are accepted?

Enter hours, minutes, and seconds in separate fields, or use formats like "2:30" or "2h 30m".

Can I calculate negative time?

If a subtraction results in negative time, the result will indicate the absolute difference. Time cannot be truly negative.

How accurate is the calculation?

Results are precise to the second. For millisecond precision, specialized tools are needed.

Can I add more than two times?

Yes! Add as many time entries as needed. The tool sums all entries together.

Does it handle days?

Results exceeding 24 hours display as hours (e.g., 26h 30m) rather than converting to days, which is standard for duration calculations.

Is this for time of day or duration?

This calculator is primarily for durations (lengths of time), not clock time conversion. For time zones, see our Timezone Converter.

Time Conversion Reference

From	To	Multiply/Divide
Hours	Minutes	× 60
Minutes	Hours	÷ 60
Minutes	Seconds	× 60
Seconds	Minutes	÷ 60
Hours	Seconds	× 3600

Pro Tips

Be consistent — Use the same format throughout your calculations
Double-check entries — Time typos are easy to make
Use for estimates — Round complex times to nearest 5-minute increments for planning
Break down large calculations — Add times in groups for easier verification

Related Tools

Explore more time and date utilities:

Hour Calculator — Focused on hours
Date Calculator — Days between dates
Timezone Converter — Convert time zones
Timestamp Converter — Unix timestamps
Deadline Calculator — Project deadlines

Enter your time values above to add or subtract durations instantly. Perfect for timesheets, project tracking, and any time-based calculations.