MEASUREMENTS AND PURCHASE DECISIONS
Distinguish person-hours from scheduled working days.
Why does a larger crew not change the total supplied person-hour estimate?
Use the matching calculator
Use this decision sequence
- Start with required task quantity and supplied productivity per person-hour.
- Calculate productive person-hours.
- Divide by crew size and productive hours per person per day.
- Keep nonproductive time, dependencies and non-linear crew effects outside this simple model unless supplied separately.
Keep the quantities distinct
| Quantity or assumption | How to use it |
|---|---|
| Person-hours | Quantity divided by productivity. |
| Crew duration | Person-hours divided by productive crew hours per day. |
| Calendar completion | Also depends on your actual working schedule. |
Worked comparison
For 120 units at a supplied rate of 5 units per person-hour, effort is 24 person-hours. Three workers each contributing 4 productive hours per day provide 12 person-hours daily, giving 2 working days.
Check before using the estimate
The calculation does not determine safe staffing or promise productivity from a particular crew.
All dimensions, product properties, prices and specifications in this example are illustrative arithmetic inputs. Use the values from your measured plan, selected product data sheet and supplier quote. This guide does not choose construction specifications or certify safety.
Calculation and scope checked 2026-10-04. Methods and scope.