# Online glass U-value, SHGC & shading coefficient calculator

 U-valueU-value: the overall air-to-air thermal transmittance of the glass = W/(m2K) SHGCSHGC: solar heat gain coefficient; it is called total solar energy transmittance (TSET) in ISO 9050/EN410 = Shading coefficientShading coefficient (SC-value): SC = SHGC/0.87 =
 Number of glass layers:Maximum 3 layers. A glass laminate is considered 1 layerSingleDoubleTriple Calculation standard:ISO 10292EN 673 Calculate SHGC?To calculate SHGC and shading coefficient; limited to single layer glass only
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, V2.1.0, 27/05/2022

## 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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### 9 thoughts on “Online glass U-value & SHGC calculator”

• 15/07/2021 at 5:32 pm

WE window single glass of of 067 SHGC ..

Recommends to us low SHGC near to 0.3

from K.Sankar
Mahindra & Mahindra
Manager-Maintenance
mob. 9600145953

• 19/07/2021 at 8:54 am

Hi, Sankar,

For SHGC = 0.3, you may select single glazing glasses with low transmittance and low-e coating on the indoor side. Please check with glass manufacturers for possible glasses. In that case, the visible light transmittance of the glass would be low.

• 19/03/2022 at 4:15 pm

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.

• 14/07/2022 at 8:56 am

Is it possible to calculate the SHGC values for double and triple glazed units?

• 14/07/2022 at 11:25 am

Hi, Mike,

For U-value calculations, only simple user inputs are required, e.g. glass and gap thicknesses. The only input requiring some technical knowledge is glass surface emissivity.

For SHGC calculations, more inputs are required and a simple online calculator is not sufficient. You may want to consider LBNL WINDOW software for glass SHGC calculation.

• 11/02/2024 at 7:24 pm