Hours Calculator — Free Online Hours Between Two Times

How to Use the Hours Calculator

1. Enter the start time: Use the Hour (0-23) and Minute (0-59) fields under "Start Time" to set when your time period begins. The calculator uses 24-hour format, so 3:00 PM is entered as hour 15. The default start time is 9:00, representing a typical workday start.
2. Enter the end time: Use the corresponding Hour and Minute fields under "End Time" to set when your time period ends. The default is 17:00 (5:00 PM), the standard end of an 8-hour workday.
3. Enable Crosses Midnight if applicable: If your end time is on the following day (for example, a night shift from 22:00 to 06:00), toggle the "Crosses Midnight" switch. This tells the calculator to add 24 hours to the end time internally, producing the correct duration instead of a 16-hour backward calculation.
4. Review the results: The results panel shows the duration in hours and minutes prominently, along with total minutes, decimal hours, and a formatted summary showing the time range. Decimal hours are particularly useful for payroll and billing applications where time needs to be multiplied by hourly rates.

All results update instantly as you change inputs. Try different time combinations to compare shift lengths, plan meetings, or estimate travel durations.

Hours Calculation Formula

Variables Explained

• Start Time (minutes): Calculated as Start Hour x 60 + Start Minute. For example, 9:30 becomes (9 x 60) + 30 = 570 minutes from midnight.
• End Time (minutes): Calculated as End Hour x 60 + End Minute. For 17:00, this is (17 x 60) + 0 = 1,020 minutes from midnight.
• 1,440: The total number of minutes in a 24-hour day. This constant is added to the end time when the Crosses Midnight option is enabled to account for the day transition.
• Duration (minutes): The absolute difference between end and start times, expressed in total minutes. This is then divided by 60 to extract hours and the remainder gives minutes.
• Decimal Hours: The duration expressed as a decimal number. Calculated by dividing total minutes by 60. For example, 480 minutes / 60 = 8.00 decimal hours.

Step-by-Step Example

Calculate hours from 9:15 to 17:45:

1. Convert start time: (9 x 60) + 15 = 555 minutes
2. Convert end time: (17 x 60) + 45 = 1,065 minutes
3. Calculate difference: 1,065 - 555 = 510 minutes
4. Extract hours: floor(510 / 60) = 8 hours
5. Extract remaining minutes: 510 mod 60 = 30 minutes
6. Calculate decimal hours: 510 / 60 = 8.50
7. Result: 8 hours 30 minutes (8.50 decimal hours)

Practical Examples

Example 1: David's Standard Workday

David works from 8:30 AM to 5:00 PM with a 30-minute lunch break. He needs to log his hours for his timesheet. Using the hours calculator with start time 8:30 and end time 17:00:

• Start: 08:30, End: 17:00
• Total time: 8 hours 30 minutes (510 minutes)
• Minus 30-minute lunch: 8 hours 0 minutes
• Decimal hours for timesheet: 8.00

David logs 8.00 hours on his timesheet. His company pays overtime after 40 hours per week, so he uses the calculator each day to track whether he is approaching the overtime threshold. For weekly tracking with automatic break deductions, our time card calculator handles this automatically.

Example 2: Maria's Night Shift

Maria is a nurse working the night shift from 11:00 PM to 7:30 AM. She enables the Crosses Midnight toggle since her shift spans two calendar days:

• Start: 23:00, End: 07:30, Crosses Midnight: On
• Total time: 8 hours 30 minutes
• Total minutes: 510
• Decimal hours: 8.50

Without the Crosses Midnight toggle, the calculator would show 15 hours 30 minutes (the backward duration from 07:30 to 23:00). The toggle correctly interprets the overnight shift as 8 hours 30 minutes. Maria converts this to 8.50 decimal hours for her payroll system.

Example 3: Tom's Freelance Billing

Tom is a freelance web developer who bills clients hourly at $120/hour. He started working on a project at 13:15 and finished at 18:45. He needs to calculate billable hours for his invoice:

• Start: 13:15, End: 18:45
• Duration: 5 hours 30 minutes
• Decimal hours: 5.50
• Invoice amount: 5.50 x $120 = $660

Tom bills 5.50 hours at $120/hour for a total of $660. The decimal hours format makes multiplication straightforward, which is why many billing systems prefer this format over hours-and-minutes. For financial calculations, our days between dates calculator can help track project timelines.

Example 4: Lisa's Study Session Planning

Lisa is preparing for final exams and wants to track her study hours. She studies from 19:00 to 23:45 on weekday evenings. She wants to know how many hours she is putting in per session:

• Start: 19:00, End: 23:45
• Duration: 4 hours 45 minutes
• Total minutes: 285
• Decimal hours: 4.75

Lisa studies 4.75 hours per session. Over a five-day week, that totals 23.75 hours of focused study time. She can adjust her schedule based on these calculations to meet her target of 25 study hours per week.

Decimal Hours Conversion Reference Table

Tips and Complete Guide

Payroll and Timesheet Applications

For payroll purposes, most employers require time entries in decimal hours because it simplifies wage calculations. To convert your hours and minutes to decimal format, divide the minutes portion by 60 and add it to the whole hours. For example, 7 hours 45 minutes becomes 7 + (45/60) = 7.75 hours. At a rate of $25/hour, that equals $193.75. Our calculator automatically provides this decimal conversion, saving you the manual math. Many payroll systems round to the nearest quarter hour (0.25), so check your employer's rounding policy.

Understanding the Fair Labor Standards Act

Under the U.S. Fair Labor Standards Act (FLSA), non-exempt employees must receive overtime pay at 1.5 times their regular rate for hours worked beyond 40 in a workweek. Accurate hour calculation is essential for both employers and employees. If you work 42.5 hours in a week, 40 hours are paid at the regular rate and 2.5 hours at 1.5x. Our hours calculator helps you track daily hours precisely so you can determine whether you are approaching or exceeding the weekly overtime threshold.

Working with Different Time Zones

If you are tracking hours for a remote team across time zones, first convert all times to a common time zone (usually UTC or your company's headquarters time zone) before calculating durations. For example, if a team member in London (UTC+0) works from 9:00 to 17:00, and you are tracking in New York time (UTC-5), their work hours translate to 4:00 AM to 12:00 PM ET. Our time zone calculator can help with these conversions.

Common Mistakes to Avoid

• Forgetting the midnight toggle for overnight shifts: If your end time is earlier than your start time and you do not enable Crosses Midnight, the calculator computes the reverse duration. Always check that the result matches your expectation for overnight periods.
• Confusing decimal hours with hours and minutes: 7.5 decimal hours is 7 hours 30 minutes, not 7 hours 50 minutes. The decimal portion represents a fraction of 60 minutes, not a percentage. This is the most common error in payroll calculations.
• Not deducting break time: The hours calculator shows total time between start and end. If you take breaks, you need to subtract them manually. For automatic break handling, use the time card calculator.
• Using 12-hour format values: Entering 5 when you mean 5:00 PM (17:00) will calculate from morning, not afternoon. Double-check that you have converted PM times by adding 12 to the hour.
• Rounding too early: If you need decimal hours for billing, use the exact decimal value rather than rounding the hours and minutes separately. Rounding 7 hours 22 minutes to 7 hours 20 minutes before converting loses 2 minutes of billable time per entry.

Frequently Asked Questions