Foundation Diagonal Calculator
Verify foundation squareness with pass/fail tolerance checks. Supports mixed inputs for construction site accuracy.
About
Pouring concrete is an irreversible process. Foundations that are out-of-square cause cascading issues for framing, flooring, and roofing. This calculator is designed for site engineers and contractors to verify formwork before the pour. It compares the theoretical diagonal against the field-measured diagonal.
Standard construction tolerances (e.g., ACI 117) often dictate maximum allowable deviations. This tool calculates the exact error delta and indicates a Pass or Fail status based on your specified tolerance threshold, ensuring compliance with architectural specifications.
Formulas
The theoretical diagonal dth is calculated via Pythagoras. The error E is the absolute difference between theoretical and measured values.
Pass Logic:
Reference Data
| Structure Size (ft) | Theoretical Diagonal (ft) | Allowable Tolerance (in) | Standard |
|---|---|---|---|
| 10 × 10 | 14.142 | ±0.5 | Rough Grade |
| 20 × 20 | 28.284 | ±0.5 | Residential |
| 30 × 40 | 50.000 | ±0.25 | Precision Work |
| 40 × 60 | 72.111 | ±0.75 | Commercial |
| 50 × 100 | 111.803 | ±1.0 | Industrial |
| 100 × 200 | 223.607 | ±1.5 | Large Slab |