Online glass U-value & SHGC calculator

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Online glass U-value, SHGC & shading coefficient calculator

U-value
U-value: the overall air-to-air thermal transmittance of the glass
 =  W/(m2K)
SHGC
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
 = 
Thickness [mm]:
The thickness of your glass in mm. Auto-calculated for a laminated glass
Emissivity, front:
Emissivty of the glass surface facing outdoor side. Use 0.837 for an uncoated glass surface
Emissivity, back:
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
Laminated 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
©OTM Solutions Pte Ltd, V2.0.0, 28/06/2020

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

The U-value calculation is compliant to ISO 10292/EN673; the SHGC & shading coefficient calculation is compliant to ISO 9050/EN 410.

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?

Please refer to the glass testing service page. Our lab is SAC-SINGLAS (ISO 17025) accredited and qualified for IGDB/CGDB submission. Our customers are from more than 20 countries.

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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.

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