How to Calculate Formwork
What is Formwork?
Formwork Calculator helps contractors and tradespeople accurately size, spec, and estimate materials and systems.
Formula
Formwork Area = Perimeter × Pour Height + Bottom if elevated
Step-by-Step Guide
- 1Measure all surfaces to be formed, add waste factor (10-15%)
- 2Apply the formula using your project measurements
- 3Add required safety factors or waste allowances per code
Worked Examples
Input
20 ft × 30 ft × 1 ft slab perimeter forms
Result
Perimeter = 100 lf × 1 ft = 100 sf forms
Common Mistakes to Avoid
- ✕Not applying code-required safety factors or derating
- ✕Forgetting to account for waste and cut losses in material estimates
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