Skip to content
Pressed glass & molded optics · Made to drawings and samples

ENGINEERING REFERENCE TOOLS

Glass Engineering Calculator

Use these bench-side tools for early weight, lighting, lens and thermal estimates. Every result shows its inputs and assumptions. Final values must be confirmed against the approved component drawing, glass material and complete luminaire assembly.

Runs in your browserNo account requiredNo input data is stored
01

Flat Glass Weight Calculator

Estimate the mass of a rectangular glass window or circular disc from nominal dimensions and density.

Mass = volume × density

View custom glass windows →
Estimated mass0.375 kgRectangle · 200 × 150 × 5 mm · density 2.50 g/cm³
02

Conical Lamp Shade Weight Estimate

Estimate the side-wall mass of a simple conical or frustum-shaped glass shade. The calculation excludes necks, flanges, ribs, feet and local wall variation.

Approximate volume = frustum side area × wall thickness

View conical glass lamp shades →
Estimated side-wall mass0.711 kgSimple frustum estimate; production mass depends on the molded profile.
03

Beam Diameter and Average Illuminance

Estimate the geometric beam diameter at a target distance and the average illuminance if the transmitted lumens were distributed uniformly inside that circle.

Diameter = 2 × distance × tan(full beam angle ÷ 2)

View custom lighting glass lenses →
Beam diameter / average illuminance2.679 m · 479 luxUniform circular-beam estimate; measured photometry will differ.
04

Spherical Lens Sag Calculator

Calculate the center sag of a spherical surface from clear aperture and radius of curvature. This is a geometry calculation, not a complete optical prescription.

Sag = R − √(R² − (D ÷ 2)²)

View molded glass lenses →
Spherical surface sag5.838 mmValid when radius is at least half the clear aperture.
05

Linear Thermal Expansion Estimate

Estimate a dimensional change over a temperature interval using a selected linear expansion coefficient. Use the coefficient from the approved material data for final work.

ΔL = original length × CTE × temperature change

Review glass material selection →
Length change / final length+0.324 mm · 200.324 mmLinear estimate using 9.0 × 10⁻⁶/K over +180°C.

Use Calculator Results as Screening Data

Calculated values do not define production tolerance, safe working temperature, pressure resistance, impact rating, photometric performance or certification. Send the component drawing and assembly conditions to info@lampoptics.com for a manufacturing review.

View all products →
View all applications →