Tempered Glass Thickness Selector Calculator

Input dimensions, loads, edge support, and deflection criteria to guide glass selection. Automatic safety factors compare stress against allowable tempered strength for reliable sizing. See thickness options, weights, and cut-sheet friendly PDF export with inputs captured. Fast, clear results for builders and fabricators everywhere.

Inputs
Panel, load & criteria
Metric mode
Multiply pressure by this factor if needed.
Simplified factor; higher for harsher exposure.
Coefficients vary with aspect ratio; see Formula section.
Typical tempered ~120 MPa (ultimate).
Allowable = ultimate / safety factor.
E (GPa) ν
Young's modulus and Poisson's ratio.
Results export includes inputs, pass/fail table, and recommendation.
Examples
Sample panels & loads
# Width Height Pressure Support Defl Note
1 900 mm 1200 mm 0.5 kPa Four edges simply supported L/90 Interior partition pane
2 1000 mm 1800 mm 0.75 kPa Four edges fixed L/120 Guarded storefront lite
3 1200 mm 2400 mm 1.0 kPa Two short edges supported L/60 Sidelite between mullions
Click “Load Example” to copy row 1 into inputs (Metric).
Results
Recommended thickness & checks
Density 2500 kg/m³ assumed
Run a calculation to see summary.
Nominal thickness Thickness (mm / in) Stress (MPa) Deflection (mm) Stress OK? Deflection OK?
Formula
Method & assumptions

This selector approximates plate behavior under uniform pressure using classical elastic plate theory. For a rectangular pane (short side a, long side b), the peak surface stress and maximum center deflection are estimated as:

  • σmax ≈ k · q · a² / t², where k depends on aspect ratio and boundary support.
  • wmax ≈ c · q · a⁴ / (E · t³), where c depends on aspect ratio and boundary support.

Allowable bending stress is taken as σallow = σult / SF. Deflection is checked against L/R where L is the short side and R is the selected limit (e.g., L/90).

Coefficients k and c are representative for common support conditions and aspect ratios (1–3) and are linearly interpolated. This is a screening tool; project-specific design standards (e.g., lab-tested charts) govern.

Guide
How to use this calculator
  1. Select units and enter width and height of the clear pane.
  2. Choose load mode: direct design pressure or wind speed (simplified conversion).
  3. Pick edge support and deflection limit; confirm material properties and safety factor.
  4. Press Calculate to evaluate common nominal thicknesses.
  5. Review pass/fail table and the recommended minimum thickness.
  6. Export CSV/PDF for submittals or attach to project notes.

Disclaimer: This tool provides preliminary guidance only and does not replace project-specific engineering or applicable standards.

FAQ
Frequently asked questions

Any width and height you enter; the tool uses the short side for span L.

Yes. Enter a different ultimate strength to represent annealed or heat-strengthened glass.

A simplified relation converts wind speed to pressure and multiplies by an exposure coefficient for site conditions.

They represent common cases. For critical applications, use tested charts or code-based procedures.

Self-weight is typically negligible compared with wind/impact. Panel weight is reported for handling and supports.

Many storefront panes use L/90 to L/120. Tighter limits reduce distortion but may require thicker glass.

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Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.