Calculator Inputs
Use generic presets as starting points, then adjust values to match your drawings, specification notes, or inspection plan.
Formula Used
d = √(x² + y²)
Tr = H ÷ N
Ta = Tr + F
Use the direct override when entered. Otherwise apply the cap to the adjusted tolerance when a cap is entered.
Slope % = (d ÷ H) × 100
θ = arctan(d ÷ H)
Where H is measured height, N is the selected denominator, F is fixed allowance, and x and y are measured top offsets from true vertical.
How to Use This Calculator
- Enter an element name and select the element type.
- Input the measured height using your field unit.
- Enter top offsets in X and Y from the plumb reference line.
- Choose a preset or type a custom ratio denominator.
- Add a fixed allowance when project rules allow one.
- Apply a cap to limit tall-element tolerance growth.
- Enter a direct override when the specification gives one exact allowable value.
- Submit the form to view pass or fail, utilization, angle, slope, and the Plotly tolerance plot above the form.
Example Data Table
| Element | Height | Offset X | Offset Y | Tolerance Rule | Actual Deviation | Allowable | Status |
|---|---|---|---|---|---|---|---|
| Column A1 | 3,000 mm | 3 mm | 4 mm | H/500 | 5.00 mm | 6.00 mm | Pass |
| Wall B2 | 4,200 mm | 8 mm | 6 mm | H/600 | 10.00 mm | 7.00 mm | Fail |
| Frame C3 | 2,400 mm | 2 mm | 1 mm | H/360 + 2 mm | 2.24 mm | 8.67 mm | Pass |
| Facade D4 | 5,000 mm | 9 mm | 7 mm | H/500, cap 10 mm | 11.40 mm | 10.00 mm | Fail |
Frequently Asked Questions
1. What is plumbness tolerance?
Plumbness tolerance is the maximum allowed horizontal deviation from true vertical over a measured height. It helps determine whether walls, columns, and frames stay within acceptable construction alignment limits.
2. Why enter both X and Y offsets?
Two-axis offsets capture lean in both directions. The calculator combines them into one resultant deviation, which better reflects actual out-of-plumb behavior than checking only one face.
3. What does H/500 mean?
H/500 means allowable deviation equals measured height divided by 500. A 3,000 mm element would allow 6 mm before caps, overrides, or added allowance are applied.
4. What is the fixed allowance field for?
Fixed allowance adds a constant value to the ratio-based limit. Use it only when contract documents, inspection plans, or internal quality rules permit that extra margin.
5. Why would I use a maximum cap?
A cap prevents very tall elements from gaining an excessive allowable deviation. It keeps tolerance limits practical when drawings or specifications set a hard maximum value.
6. Does a pass result mean the work is perfect?
No. Pass only means the measured plumbness deviation is within the entered tolerance. Separate checks may still be needed for twist, bow, finish quality, and connection fit.
7. Which units should I choose?
Use the units closest to your field measurements. The calculator converts values internally, so you can work in millimeters, centimeters, meters, inches, or feet.
8. Can I export the result?
Yes. After calculation, use the CSV button for records or the PDF button for a quick inspection summary during QA reviews and site reporting.