Knowing how to calculate Man hour is very important as it can be used as a key performance indicator. Man hour is the total hour worked over a specific period of time. As a health and safety personnel you need to understand how to calculate man-hour since it is necessary for determining the health and Safety performance.
Man-hours are a crucial element in submitting a winning project bid as well as charging for work completed. Because labor constitutes such a large portion of any contract work, estimating and reporting hours accurately is crucial to having a successful business.
How To Calculate Man Hours
How to calculate man hours formula =
Total hours work a day per worker x Total number of workers x Total numbers of days worked over the specific period of time
Example:
Consider that:
- Number of hours worked a day per worker: 8 hours
- Total number of workers: 20 workers
- Specific period of time: 3 months – 90 days (January – March), minus weekends and public holidays.
Assuming that weekend and public holidays = 24 days
We subtract 24 from the number of days within the 3 months
90 – 24 = 66 days
Hence;
Man-hour = 8 x 20 x 66
= 10,560 hours.
From the example above, man-hour is calculated from simple parameter.
You can substitute the values with your organization’s specific value to determine the man-hour for a specific period for your organization.
Note that: Man-hour is an integral factor in measuring Health and safety performance.
An organization that records 5 LTI in every 10,000 man-hour every 3 months and the organization that record 10 LTI in every 100,000 man-hour every 3 month poses different Health and safety performance level. Judging by the man-hour and the LTI recorded, the second organization has a better Health and Safety performance.
Man-hours exclude the breaks that people generally require from work, e.g. for rest, eating, and other bodily functions. They count only pure labor. Managers count the man-hours and add break time to estimate the amount of time a task will actually take to complete. Thus, while one college course’s written paper might require twenty man-hours to carry out, it almost certainly will not get done in twenty consecutive hours. Its progress will be interrupted by work for other courses, meals, sleep, and other human necessities.
Calculating Man Hours Per Day
Lets express this mathematically, having in mind the formular for calculating man hour expressed above.
Recap:
Total Man Hour = Total hours work a day per worker x Total number of workers x Total numbers of days worked over the specific period of time
For a day: Total hours work a day per worker x Total number of workers
N/B: Average daily working hour = 8 hours;
Assuming 8 workers worked
Man Hour A day = 8 x 8
= 64 Man Hour.
There are situations where an employee work for more the 8 hours a day, in this case the number of hours work will be used instead of the average daily working hours.
Calculating Man Hours Per Week
Mathematically, having in mind the formular for calculating man hour expressed above.
Recap:
Total Man Hour = Total hours work a day per worker x Total number of workers x Total numbers of days worked over the specific period of time
For a week: Total hours work a week per worker x Total number of workers
N/B:
Average daily working hour = 8 hours
Average days in a week = 5 Days
Total hours work a week per worker = 8 x 5
Total hours work a week per worker = 40
== Assuming 8 workers worked
Man Hour the week = 40 x 8
Total manhour for the week = 320 Man Hour.
Calculating Man Hours Per Month
Mathematically, having in mind the formular for calculating man hour expressed above.
Recap:
Total Man Hour = Total hours work a day per worker x Total number of workers x Total numbers of days worked over the specific period of time
For a Month: Total hours work a Month per worker x Total number of workers
N/B:
Average daily working hour = 8 hours
Average days in a week = 5 Days
Average weeks in a month = 4 Weeks
Total hours work a Month per worker = 8 x 5 x 4
Total hours work a week per worker = 160
== Assuming 8 workers worked
Man Hour the month = 160 x 8
Total manhour for the week = 1280 Man Hour.
Calculating Man Hours Per Project
If you have a static number of employee and working hour through out the project lifetime, what you just need to do is to multiply the monthly manhour by the number of months.
Lets say;
Monthly manhour = 1280
Number of Months worked = 12 Months
man Hour for the project = 1280 X 12
Total manhour for the project = 15360
Significance of Manhour
One significance of manhour is that by dividing the total number of man-hours by the total number of workers available, the man-hour concept has the advantage of allowing one to calculate the impact of staff changes on the total amount of time needed for a task. A team of two workers will finish a task that requires twenty man-hours in ten hours, whereas a team of five workers will finish it in four hours.
Conclusion
Man Hour is a metric for key performance indicator (KPI), as a Safety professional you should know how to calculate this metric. With this blog post, you should not have any issue with calculating Manhour; be it daily, weekly, monthly or total man our for your project.
Do all that you can to stay safe and keep your workplace safe.
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