Rechnerpilot Calculator
Project Time Calculator
Sum task durations into a project effort and optionally convert them into workdays or person-days at a freely selectable number of hours per workday.
Explanation
How Project Time Calculator works
The project time calculator adds the duration of individual tasks into a total effort. Optionally, the effort is converted into workdays or person-days via the hours per workday.
Total effort and workdays
Total efforttotal effort = sum of all task durationsAll task durations are summed in minutes and output as hours and minutes.
Workdaysworking days = total hours / hours per working dayThe total effort in hours is divided by the hours per workday.
Practice
Practical examples
For illustration only – your own calculation is what counts.
Effort of a small project
Concept 4 h 30 min, implementation 12 h, testing and acceptance 3 h 15 min at 8 hours per workday.
Result: The total effort is 19 h 45 min (19.75 hours) and corresponds to 2.47 workdays or person-days.
Two full workdays
Two tasks of 8 hours each at 8 hours per workday.
Result: The total effort is 16 h 0 min (16 hours) and corresponds to 2 workdays.
Single task
A single task of 1 h 30 min at the default 8 hours per workday.
Result: The total effort is 1 h 30 min (1.5 hours) and corresponds to 0.19 workdays.
- Entering more than 59 minutes
Minutes of 60 or more belong in the hours field, not in the minutes field.
Enter full hours in the hours field and only the remainder (0 to 59) in the minutes field.
- Wrong hours per workday
If the daily working time is set too high or too low, it distorts the workdays.
Use the actually planned daily working time as the basis.
FAQ
Frequently asked questions
What does the project time calculator compute?
It sums the duration of several tasks into a total effort and optionally converts it into workdays or person-days.
What is the difference between workdays and person-days?
Mathematically both are the same: the total effort is divided by the hours per workday. If only one person works, one person-day equals one workday.
How many hours per workday should I enter?
The default is 8 hours. You can adjust the value to your actual daily working time, for example 6 or 7.5 hours.
How many tasks can I enter?
Up to six tasks, each with hours and minutes. Empty rows are ignored; only tasks with a duration greater than zero are counted.
Why are the minutes limited to 0 to 59?
Minutes and hours are entered separately. Values of 60 minutes or more should be entered as an additional hour so the sum stays unambiguous.
Does the calculator also plan deadlines or resources?
No. The calculator only sums efforts. Calendars, deadlines, dependencies or resource allocation are not part of the calculation.
- The calculator only sums efforts and does not plan any deadlines or resources.
- Workdays and person-days are mathematically the same; parallel work by several people is not represented.
Related calculators
More tools