Enter the amount of solar radiation coming into a surface and the amount of radiation coming off the surface to determine the total solar reflectance.

Total Solar Reflectance Formula

The following formula is used to calculate the total solar reflectance percentage.

TSR = OSR / ISR * 100

  • Where TSR is the Total Solar Reflectance (%)
  • OSR is the outbound or reflected radiation
  • ISR is the inbound radiation from the sun

To calculate a Total Solar Reflectance, divide the amount of radiation reflected by the inbound radiation and then multiply by 100 to get the TSR percentage.

What is Total Solar Reflectance?


Total Solar Reflectance, or TSR for short, is a measure of the percentage of solar radiation that a surface reflects. The amount that a surface reflects is dependent on the color and material.

How to calculate Total Solar Reflectance?

Example Problem:

The following example outlines how to calculate TSR of a surface.

First, determine the inbound solar radiation. In this example, the surface is receiving a total of 500 solar radiation.

Next, determine the total amount of solar radiation that is reflected. In this case, the amount reflected is 250.

Finally, calculate the TSR using the formula above:

TSR = OSR / ISR * 100

TSR = 250 / 500 * 100

TSR = 50%