Time Calculator

Add or subtract hours, minutes, and seconds. Find the duration between two times. Convert between HH:MM:SS format, decimal hours, and total minutes for payroll and time tracking.

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Add or Subtract Time

Start Time

Hours : Minutes : Seconds

Operation

Time to Add/Subtract

Hours : Minutes : Seconds

Time Between Two Times

From

Time Duration

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Duration

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Decimal Hours

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Total Minutes

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Total Seconds

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Decimal Hours Conversion Table

Minutes	Decimal Hours	Minutes	Decimal Hours	Minutes	Decimal Hours
5 min	0.08	20 min	0.33	40 min	0.67
10 min	0.17	25 min	0.42	45 min	0.75
15 min	0.25	30 min	0.50	50 min	0.83

Decimal hours = minutes ÷ 60. Most payroll systems require time in decimal format. For example, 7 hours 45 minutes = 7.75 decimal hours.

Common Work Schedule Calculations

Schedule	Daily Hours	Weekly Hours	Annual Hours	With 2 Weeks PTO
Standard (9-5)	8.0	40.0	2,080	2,000
With 30-min lunch	7.5	37.5	1,950	1,875
With 1-hour lunch	7.0	35.0	1,820	1,750
4/10 schedule	10.0	40.0	2,080	2,000
Part-time (6 hrs)	6.0	30.0	1,560	1,500

Understanding Time Calculations

Time arithmetic differs from regular math because it uses base-60 (sexagesimal) rather than base-10. Adding 45 minutes to 30 minutes gives 1 hour 15 minutes, not 75 minutes in clock format. This base-60 system dates back to ancient Babylon (circa 2000 BC) and persists because 60 is highly divisible — it divides evenly by 1, 2, 3, 4, 5, 6, 10, 12, 15, 20, and 30, making fractional time calculations convenient.

Decimal Hours for Payroll

Most payroll and billing systems require time in decimal format rather than hours:minutes. To convert: divide the minutes by 60 and add to the hours. For example, 8 hours 45 minutes = 8 + (45/60) = 8.75 decimal hours. At $25/hour, that's $218.75 in pay. Getting this conversion wrong is one of the most common payroll errors — the Department of Labor reports that time tracking errors affect approximately 8% of payroll calculations, costing US businesses an estimated $7.4 billion annually.

For calculating pay from hours worked, see our Hours Calculator. For date-based calculations, use the Date Calculator. Optimize your schedule with the Sleep Calculator.

Frequently Asked Questions

How do I add hours and minutes?

Add hours and minutes separately. If minutes exceed 60, carry over: 3h 45m + 2h 30m = 5h 75m = 6h 15m. This calculator handles the carry-over automatically for hours, minutes, and seconds.

How do I convert minutes to decimal hours?

Divide minutes by 60. Common conversions: 15 min = 0.25, 30 min = 0.50, 45 min = 0.75. For example, 7 hours 20 minutes = 7 + 20/60 = 7.33 decimal hours. Most payroll and billing systems require this format.

How many hours are between 9 AM and 5:30 PM?

8 hours 30 minutes (8.5 decimal hours). Use the "Time Between" tool above — enter 9:00 AM and 5:30 PM. Subtracting a lunch break (e.g., 30 minutes) gives 8 hours of actual work time.

How many work hours in a year?

A standard full-time year is 2,080 hours (40 hours/week × 52 weeks). After subtracting typical PTO (10 days = 80 hours), that's about 2,000 hours. Federal holidays (11 days) would further reduce it to ~1,912 actual working hours.

What's the difference between elapsed time and clock time?

Elapsed time is the duration between two moments (e.g., 3 hours 15 minutes). Clock time is a specific point on the clock (e.g., 2:30 PM). This calculator computes both: add/subtract gives you a clock time result, and "Time Between" gives you elapsed duration.

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