Time Calculator

Add or subtract time, calculate differences, convert units, and express durations in multiple formats.

Add or Subtract Time

Hours
:
Minutes
:
Seconds
Hours
:
Minutes
:
Seconds
Result
13:30:00
12:00:00 + 1h 30m 0s

Calculate Time Difference

Hours
:
Minutes
:
Seconds
Hours
:
Minutes
:
Seconds
Time Difference
8h 30m 0s
From 09:00:00 to 17:30:00
Total Hours
8.5
Total Minutes
510
Total Seconds
30,600

Convert Time Units

Conversions
Seconds
3,600
Minutes
60
Hours
1
Days
0.041667
Weeks
0.005952

Express Duration As Different Formats

Hours
:
Minutes
:
Seconds
Duration Expressed As
Total Seconds
13,530
Total Minutes
225.5
Total Hours
3.7583
Formatted
03:45:30

Time Calculation Tips

24-Hour Format

This calculator uses 24-hour format (0-23 hours). For PM times, add 12 to the hour (e.g., 2 PM = 14:00).

Day Rollover

When adding time causes the result to exceed 24 hours or go below 0, the calculator shows the day change indicator.

Decimal Time

Decimal hours are useful for timesheets. 1.5 hours = 1 hour 30 minutes. 0.25 hours = 15 minutes.