Duration Calculator

Convert each time unit to seconds, sum them, then convert back to hours:minutes:seconds.

Convert 2 hours, 45 minutes, 30 seconds to total seconds:

Convert 9930 seconds back:

• Hours: $\\lfloor 9930 \\div 3600 \\rfloor = 2$ hours
• Remaining: $9930 - (2 \\times 3600) = 2730$ seconds
• Minutes: $\\lfloor 2730 \\div 60 \\rfloor = 45$ minutes
• Seconds: $2730 - (45 \\times 60) = 30$ seconds
• Result: 2:45:30

1. Enter hours, minutes, and seconds
2. Click "Calculate" to see the duration in different formats

| Hours | Minutes | Seconds | |-------|---------|---------| | 1 | 60 | 3,600 | | 2 | 120 | 7,200 | | 3 | 180 | 10,800 | | 4 | 240 | 14,400 | | 5 | 300 | 18,000 | | 6 | 360 | 21,600 | | 12 | 720 | 43,200 | | 24 | 1,440 | 86,400 |

To add multiple durations, convert each to seconds, sum them, then convert back. This avoids carrying minutes and hours manually.

• Tracking work hours and overtime
• Calculating video or audio lengths
• Estimating travel or commute times
• Scheduling and planning
• Exercise and sports timing

Can I enter decimals? Yes, enter 1.5 for 1 hour 30 minutes, or 2.25 for 2 hours 15 minutes.

How do I convert to decimal hours? Divide total seconds by 3,600. For example, 9,930 ÷ 3,600 = 2.758 hours.

What about milliseconds? This tool works with seconds precision. For milliseconds, multiply your seconds by 1,000.

Can I subtract durations? Enter the duration to subtract as a negative value in the appropriate field.