BUILDING & PLANNING · FIELD TOOL
Each activity takes quantity ÷ (output per crew-day × crews). 400 m³ of excavation (5 days), 120 m³ of concrete (6), 600 m² of blockwork with 2 crews (12) and 1,200 m² of plaster with 2 crews (15) add up to 38 days: 42 working days with a 10% allowance, finishing about 7 weeks later on a Monday–Saturday week.
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| Estimated finish | Sat, 19 Dec 2026 |
| Activity 1 | 5.0 days 400 ÷ (80 × 1 crew) |
| Activity 2 | 6.0 days 120 ÷ (20 × 1 crew) |
| Activity 3 | 12.0 days 600 ÷ (25 × 2 crews) |
| Activity 4 | 15.0 days 1,200 ÷ (40 × 2 crews) |
A first estimate only. A programme with real dependencies, resources and approvals (critical path) gives the reliable date.
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Results are estimates for planning and material ordering only. They are not a substitute for structural design or approval by a qualified engineer. Read the full disclaimer.
Days per activity = quantity ÷ (output per crew-day × crews)
Total = first + Σ later × (1 − overlap), × (1 + allowance)
Finish = start + working days on your calendar| Activity | Quantity | Output / crew-day | Crews | Days |
|---|---|---|---|---|
| Excavation | 400 m³ | 80 | 1 | 5 |
| Concrete | 120 m³ | 20 | 1 | 6 |
| Blockwork | 600 m² | 25 | 2 | 12 |
| Plaster | 1,200 m² | 40 | 2 | 15 |
Total 38 days + 10% = 42 working days (≈ 7 weeks, Monday–Saturday).
Break the work into activities, estimate the quantity and realistic output of each crew, divide to get days, then add them in sequence (overlapping where trades can work at the same time) and add an allowance for weather and risk.
Your own past jobs are best. Published norms and supplier data help, but adjust for site access, weather, crew skill and how repetitive the work is.
No: it is a quick estimate. A proper programme maps dependencies, resources, approvals and the critical path.