What is a calculator for hours?
An hours calculator is a tool that tells you how long it is between two clock times. You tell it when you started and when you completed, and it figures out how long it took. This is not the same as adding hours together; instead, you are measuring a period of time.
The idea looks straightforward until you have to deal with problems in the actual world. What do you do after your shift ends at midnight? How do you change 8 hours and 45 minutes into the decimal format that your payroll system needs? This calculator takes care of those situations on its own and gives you payroll-ready numbers in seconds.
Employers use hours calculators to check timesheets. Freelancers depend on them to charge clients correctly. Employees check their pay stubs twice. The one thing that everyone needs to know is how long it took to get from point A to point B.
How to figure out how many hours you've worked by hand
If you know the math behind time calculations, you can check your work and find mistakes. The main formula is:
Total Hours = End Time - Start Time - Break Duration
Changing to 24-Hour Format
Switching to 24-hour (military) time gets rid of the uncertainty between AM and PM. Add 12 to any hour in the PM except for 12 PM itself.
Time in 12 hours and 24 hours
| 12-Hour Time | 24-Hour Time |
|---|---|
| 8:00 AM | 08:00 |
| 12:00 PM | 12:00 |
| 1:00 PM | 13:00 |
| 5:30 PM | 17:30 |
| 10:00 PM | 22:00 |
| 12:00 AM | 00:00 |
Changing minutes into decimal hours
Most payroll systems need decimal hours instead of hours and minutes. The conversion breaks minutes down into 60 parts.
| Minutes | Calculation | Decimal |
|---|---|---|
| 15 | 15 / 60 | 0.25 |
| 20 | 20 / 60 | 0.33 |
| 30 | 30 / 60 | 0.50 |
| 45 | 45 / 60 | 0.75 |
8 hours and 45 minutes becomes 8.75 decimal hours, which makes it much easier to multiply for payroll.
Examples in order
Standard Day Shift
Office worker, 8:30 AM to 5:00 PM, 30-min lunch
- Change: 08:30 to 17:00
- Raw duration: 17:00 - 08:30 = 8 hours and 30 minutes
- Take away lunch: 8:30 - 0:30 = 8h 0m
- Result: 8.0 decimal hours
Part-time Shift
Retail worker from 2:00 PM to 7:15 PM with no breaks
- Change: 14:00 to 19:15
- Time: 19:15 - 14:00 = 5h 15m
- Decimal: 5 + (15 / 60) = 5.25
- Result: 5.25 decimal hours
Overnight Shift
Security guard, 10 PM to 6:30 AM, 45-min break
- From midnight to midnight: 24:00 - 22:00 = 2h
- After midnight: 06:30 = 6h 30m
- Total: 8h 30m - 45m = 7h 45m
- Result: 7.75 decimal hours
Graveyard Shift
Warehouse, 11 PM to 7:30 AM, two 15-minute breaks
- Before midnight: 1 hour; After: 7 hours and 30 minutes
- Total raw: 8 hours and 30 minutes
- Total breaks: 30 minutes
- The answer is 8.0 decimal hours.
Hours calculation is often used for
Tracking Employees' Time
Hourly workers need to keep precise records for each pay period. Check your entries against your pay stubs again. Payroll mistakes happen more often than you might think.
Billing for freelancers
Freelancers that charge by the hour need to keep track of their time very carefully. Clients want accurate bills, and arguments over billable hours hurt professional relationships.
Project Management
Project managers figure out how long tasks will take and keep track of the actual hours worked compared to the expected hours. To make better guesses in the future, compare them to the original guesses.
Processing Payroll
The formula for gross pay is Decimal Hours times Hourly Rate. $25 an hour times 37.5 hours equals $937.50 in gross compensation.
Things you should not do
Not taking breaks into account
A 9-to-5 workday looks like 8 hours, but if you took an unpaid hour for lunch, you only worked 7 hours that you could bill.
Mixing up AM and PM
If you write 12:30 PM instead of 12:30 AM, you make a 12-hour mistake. Check your entries again at noon and midnight.
Not paying attention to shifts that happen at night
Figuring out that 11 PM to 7 AM is negative time gives you results that don't make sense. The math needs to take crossing midnight into account.
Rounding too soon
You should round your ultimate total, not your intermediate calculations. Rounding too soon leads to cumulative errors.
Table of Hours Reference
| Time Period | Hours |
|---|---|
| 1 Day | 24 hours |
| 1 Week | 168 hours |
| 1 Work Week (Full-Time) | 40 hours |
| 1 Month (Average) | 730 hours |
| 1 Work Month (Full-Time) | 173.33 hours |
| 1 Year | 8,760 hours |
| 1 Work Year (Full-Time) | 2,080 hours |
Questions that are often asked
How can I figure out how many hours I've worked between two times?
Take away the start time from the end time. The difference is 8 hours if you started at 9:00 AM and ended at 5:00 PM. Change both times to the same format (24-hour is the easiest), and then take away. For instance, 17:00 minus 9:00 is 8 hours worked.
How can I change minutes into decimal hours for payroll?
Take the minutes and divide them by 60. For example, 0.5 hours is the same as 30 minutes (30 / 60 = 0.5). 15 minutes is the same as 0.25 hours, 30 minutes is the same as 0.5 hours, and 45 minutes is the same as 0.75 hours. So, 8 hours and 30 minutes is the same as 8.5 decimal hours.
How can I figure out how many hours I worked with breaks?
Find the total time from start to finish, then take away the time you took off. If you worked from 9:00 AM to 5:00 PM with a 30-minute lunch break, you really only worked for 7 hours and 30 minutes, or 7.5 decimal hours.
How can I figure out how many hours I worked on an overnight shift that went past midnight?
For shifts that go all night, add up the hours from the start time to midnight and then the hours from midnight to the end time. A shift from 10:00 PM to 6:00 AM is 2 hours (10 PM to midnight) + 6 hours (midnight to 6 AM), for a total of 8 hours. This is done automatically by our calculator.
What is decimal time and why do people use it for payroll?
Decimal time shows minutes as fractions of an hour using decimals instead of the usual hours:minutes format. Decimal hours make it easier to multiply hourly salaries, which is why payroll systems use them. You don't have to figure out 8 hours and 45 minutes times a wage rate; you just multiply 8.75 hours by the rate.
What does the 7-minute rounding rule mean for time?
The 7-minute rule is a frequent way to pay people, where time is rounded to the next 15-minute mark. Minutes 1 through 7 round down, and minutes 8 through 14 round up. For instance, if you clock in at 8:07 AM, it rounds to 8:00 AM, but if you clock in at 8:08 AM, it rounds to 8:15 AM. To follow labor rules, this technique must even out over time.
What time does 9 to 5 start and end?
A shift from 9:00 AM to 5:00 PM lasts exactly 8 hours. If you take a 30-minute or 1-hour unpaid lunch break, though, your real paid work time would be 7.5 or 7 hours, respectively.
What is the best way to change military time to regular time?
Military time and normal time are the same from 00:00 to 12:00; just add AM. To get the normal hour for times after 1:00 PM, take away 12 and then add PM. So, 14:30 turns into 2:30 PM (14 minus 12 equals 2), and 17:00 turns into 5:00 PM.
Is it possible for companies to automatically take breaks out of hours worked?
Yes, in most places, employers can automatically take away lunch breaks, but only if the employees actually take those breaks. If an employee works through a break that was automatically taken away, they need to tell someone so it may be fixed. Policies about automatic deductions should be easy to understand and always followed.
How many hours of work are there in a year?
Based on 40 hours a week for 52 weeks, a conventional full-time work year has 2,080 hours. This number is sometimes used to change yearly incomes into hourly rates and the other way around. Part-time work years depend on how many hours you work.
What is pay at time and a half?
Time and a half indicates 1.5 times your regular hourly rate. This is usually what you get paid for extra hours. If you normally charge $20 an hour, time and a half would be $30 an hour. The Fair Labor Standards Act says that non-exempt employees get this pay for every hour worked over 40 in a week.
How can I figure out how many hours I've worked over several days?
Add up the totals for each day separately. For weekly timesheets, figure out how many hours you worked each day by subtracting breaks from the start and end timings. Then add up all the daily totals. Our calculator gives both individual and total figures for accurate payroll processing.
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