Hours Calculator

What this calculator does

This calculator returns the net time between two clock times, or the total net work hours across multiple days in a week. It handles unpaid breaks in minutes, treats a shift as overnight when the end time is earlier than the start time, and can separate regular and overtime hours using a threshold you set.

Formula

Net work time from a single interval:

Net work time = End time − Start time − Unpaid break

For overnight shifts, when the end time is earlier than the start time:

Gross minutes = End minutes + 1,440 − Start minutes

1,440 is the number of minutes in 24 hours.

For multiple workdays:

Weekly hours = Sum of daily net work time

For overtime with an adjustable threshold:

Regular hours = min(total hours, overtime threshold)
Overtime hours = max(total hours − overtime threshold, 0)

Variable definitions

• Start time: Beginning clock time in HH:MM.
• End time: Ending clock time in HH:MM.
• Unpaid break: Break duration in minutes to deduct from the shift.
• Overtime threshold: Hours above this value are counted as overtime. Default 40 hours, adjustable.

Step-by-step calculation

1. Choose the calculator mode.
2. Enter the start and end times.
3. Add an unpaid break if needed.
4. Add more workdays for a weekly total.
5. Adjust the overtime threshold if needed.
6. Review, copy, or share the result.

Worked example

Start time 8:30 AM, end time 5:15 PM, unpaid break 45 minutes.

• Gross duration: 8 hours 45 minutes
• Break deducted: 45 minutes
• Net work time: 8 hours
• Decimal hours: 8.00
• Total minutes: 480

How to use this calculator

Choose Between Times for one time interval or Work Week for multiple days. Enter the start and end times, add any unpaid break, then review the calculated hours in hours and minutes, decimal hours, and total minutes.

1. Choose the calculator mode.
2. Enter the start and end times.
3. Add an unpaid break if needed.
4. Add more workdays for a weekly total.
5. Edit day labels as needed, and remove any day you do not want to include using the Remove button on that row.
6. Adjust the overtime threshold if needed.
7. Review, copy, or share the result.

Common mistakes

• Forgetting to deduct an unpaid break.
• Treating an overnight shift as a negative duration.
• Entering a break longer than the work interval.
• Confusing decimal hours with hours and minutes. 8.50 decimal hours means 8 hours 30 minutes, not 8 hours 50 minutes.
• Assuming the default overtime threshold applies to every workplace or location.

What the Calculator Results Mean

In Between Times mode, the tool shows:

• Total hours: the net work time between the two clock times, after the unpaid break has been deducted, written as hours and minutes.
• Hours and minutes: the same net time in HH:MM form, based on exact integer minutes.
• Decimal hours: the net time as a decimal, rounded to two places.
• Total minutes: the exact number of net minutes.
• Gross duration: the time between the start and end times before the break is deducted.
• Break deducted: the unpaid break in minutes that was subtracted from the gross duration.

In Work Week mode, the tool shows:

• Weekly total: the sum of net work time across every valid row, written as hours and minutes.
• Total hours and minutes: the weekly total in HH:MM form.
• Decimal hours: the weekly total as a decimal, rounded to two places.
• Total minutes: the exact number of net minutes across the week.
• Total unpaid break: the sum of every deducted break, in minutes.
• Active days: the count of rows that produced a valid work time. Empty rows are ignored, and rows with an error do not count.
• Average hours per active day: the weekly total divided by the number of active days, as decimal hours.

When overtime is enabled, the tool also shows:

• Regular hours: the smaller of the weekly total and the overtime threshold.
• Overtime hours: the amount by which the weekly total exceeds the threshold, or zero if it does not.
• Overtime threshold: the number of hours you set as the boundary between regular and overtime hours.

How Overnight Shifts Are Calculated

When the end time is earlier than the start time, the calculator treats the end time as the following day. For example, a shift from 10:00 PM to 6:00 AM is an 8-hour interval before any break is deducted.

Weekly Work Hours Example

Daily net work time:

• Monday: 8 hours
• Tuesday: 8 hours 30 minutes
• Wednesday: 7 hours 30 minutes
• Thursday: 8 hours
• Friday: 9 hours

Total: 41 hours. With a 40-hour threshold, regular hours are 40 and overtime hours are 1. The overtime threshold is adjustable. This calculation does not determine whether overtime pay is legally required.

Decimal Hours vs. Hours and Minutes

Hours and minutes use 60 minutes per hour. Decimal hours express part of an hour as a decimal.

• 15 minutes = 0.25 hours
• 30 minutes = 0.50 hours
• 45 minutes = 0.75 hours

Frequently asked questions