Calculate man months from man hours, average work hours per day, and working days per month, or solve any missing value in the formula.

Man Hours To Man Months Calculator

Enter any 3 values to calculate the missing variable

Man Hours To Man Months Formula

The following formula is used to calculate the man months for a given set of inputs.

MM = MH / (H \cdot D)

Variables:

  • MM is the man months
  • MH is the man hours
  • H is the average working hours per day
  • D is the average working days per month

To calculate the man months, divide the man hours by the product of the average working hours per day and the average working days per month.

Man Hours to Man Months Conversion Table (Assumes 8 h/day, 20 working days/month)
Man Hours (h) Man Months (m)
10.006
20.013
40.025
60.038
80.050
160.100
240.150
320.200
400.250
600.375
800.500
1000.625
1200.750
1400.875
1601.000
1801.125
2001.250
2401.500
3202.000
4002.500
* Rounded to 3 decimals. Assumes 8 hours/day and 20 working days/month (1 man-month = 160 man-hours).

What is Man Hours To Man Months?

Man hours to man months is a conversion used to estimate the amount of work done or required in terms of months, given the total man hours, average working hours per day, and average working days per month. This conversion is particularly useful in project management and workforce planning to allocate resources and timelines effectively.

How to Calculate Man Hours To Man Months?

The following steps outline how to calculate the Man Hours To Man Months.


  1. First, determine the total man hours (MH).
  2. Next, determine the average working hours per day (H).
  3. Next, determine the average working days per month (D).
  4. Finally, calculate the man months using the formula MM = MH / (H * D).
  5. After inserting the values and calculating the result, check your answer with the calculator above.

Example Problem : 

Use the following variables as an example problem to test your knowledge.

Total man hours (MH) = 160

Average working hours per day (H) = 8

Average working days per month (D) = 20