Time Calculator

Use this Time Calculator to add, subtract, multiply, or divide time values, or calculate the elapsed time between two dates or date-times.

Time Calculation Methods

Add time:

Total time = time 1 + time 2

Subtract time:

Time difference = first time − second time

Multiply time:

Result = time × factor

Divide time:

Result = time ÷ factor

Between dates:

Duration = end date − start date

Between dates and times:

Elapsed duration = end date/time − start date/time

Standard time conversions include:

• 1 minute = 60 seconds
• 1 hour = 60 minutes
• 1 day = 24 hours
• 1 week = 7 days

Example

Suppose you want to add 2 hours 30 minutes and 1 hour 45 minutes.

2 hours 30 minutes + 1 hour 45 minutes = 4 hours 15 minutes

The calculator can also display the same duration in total minutes:

4 hours 15 minutes = 255 minutes

Important Notes

• Subtraction depends on the order in which the time values are entered.
• Decimal hours are different from hours and minutes. For example, 1.5 hours equals 1 hour 30 minutes.
• Months and years do not have fixed durations, so approximate month or year results should not be treated as exact calendar intervals.
• Use date or date-time mode when actual calendar dates matter.
• The calculator is not designed for time-zone conversions or daylight-saving-time comparisons between different locations.
• For payroll, legal deadlines, billing, contracts, or official records, follow the required timekeeping or calendar rules.

Sources

• BIPM — SI Base Unit: Second
• NIST — Time Unit Conversions