Online glass U-value, SHGC & shading coefficient calculator
U-value =  W/(m2K)
U-value: the overall air-to-air thermal transmittance of the glass
SHGC: solar heat gain coefficient; it is called total solar energy transmittance (TSET) in ISO 9050/EN410
Shading coefficient =
Shading coefficient (SC-value): SC=SHGC/0.87
The thickness of your glass in mm. Auto-calculated for a laminated glass
Emissivty of the glass surface facing outdoor side. Use 0.837 for an uncoated glass surface
Emissivty of the glass surface facing indoor side. Use 0.837 for an uncoated glass surface
Solar energy transmittance:
The fraction of solar energy transmitted through the glass. 0 (0%) for an opaque glass and 1 (100%) for a perfect transparent glass
Solar energy reflectance, front:
The fraction of solar energy reflected back by the glass front surface (outdoor side). 0 (0%) for a perfect black & opaque glass and 1 (100%) for a perfect white & opaque glass
Toggle this check box if your glass is a laminated glass.
Glass 1 thickness [mm]:
Thickness of glass layer 1 of the laminated glass (closer to outdoors) in mm
Interlayer thickness [mm]:
Thickness of the lamination interlayer in mm
Glass 2 thickness [mm]:
Thickness of glass layer 2 of the laminated glass (closer to indoors) in mm
How to use the online calculator?
It is easy and intuitive to use this online calculator. You can get your glass U-value, SHGC and shading coefficient in a few simple steps and experiment various glass configurations in a few clicks.
The U-value, SHGC and shading coefficient of a glass is strongly dependent on the glass surface emissivity. If you are not sure, please use the following recommended emissivity values:
- Uncoated surfaces: 0.837 (default)
- Surfaces with triple-silver soft low-e coating: 0.02
- Surfaces with double-silver soft low-e coating: 0.04
- Surfaces with single-silver soft low-e coating: 0.09
- Surfaces with hard low-e coating: 0.3
Notes on SHGC & shading coefficient calculation
The calculation of glass SHGC & shading coefficient is limited to single glazing systems only, but not for double or triple glazing systems.
This is limited by the mathematical models for SHGC & shading coefficient calculation. Full spectrophotometric data are required for double or triple glazing systems.
Additionally, in ISO 9050/EN 410, SHGC is called total solar energy transmittance.
What are glass U-value, SHGC and shading coefficient?
We have some explanations on glass U-value, SHGC and shading coefficient in the glass testing service page.
Looking for a professional glass U-value, SHGC and shading coefficient testing lab?
Related blog posts
Comments or feedback?
Please feel free to leave your comments or feedback to this online calculator in the “Leave a Reply” section at the bottom of this page. We will improve this online calculator regularly.
Work with the expert in Optical & Thermal Measurement solutions.