Measure twice, make once
Sampled project-time estimator
Scale a timed sample into a realistic working estimate with your own allowance.
The page shows its formula, example, assumptions, rounding, and limitations beside the calculator.
Sampled project-time estimator
Scale a timed sample into a realistic working estimate with your own allowance.
Formula and assumptions
Observed minutes per unit are scaled to the target, selected complexity factor, and break allowance. The result shows a ±15% planning band for ordinary pace variation. Use comparable sample and project units; include breaks in the sample or allowance, but not both.
Worked example
Example: 50 units in 20 minutes, scaled to 500 units plus 15%, gives a 3.3–4.4 hour planning range around a 3.8 hour central estimate.
Limits and rounding
Results are planning estimates from the values entered. Displayed decimals are rounded for craft use; whole materials and repeats round up where the method says so. Confirm gauge, material behavior, construction, and finished measurements before committing supplies.