Enter any u-value into the calculator to convert it into the equivalent RSI value.

U Value to RSI Calculator

Enter one value to calculate the missing variable

U Value to RSI Formula

The following equation is used to calculate the RSI from the U-value.

RSI = 1/U
  • Where RSI is the thermal resistance per unit area
  • U is the u-value

To calculate the RSI, divide 1 by the u-value.

U-value to RSI Conversion Table (SI Units)
U-value W/(m²·K) RSI m²·K/W
0.1010.000
0.156.667
0.205.000
0.254.000
0.303.333
0.352.857
0.402.500
0.452.222
0.502.000
0.601.667
0.701.429
0.801.250
0.901.111
1.001.000
1.200.833
1.400.714
1.600.625
1.800.556
2.000.500
3.000.333
* Rounded to 3 decimals. Relationship: RSI = 1 / U (SI units). For imperial conversions: 1 BTU/(hr·ft²·°F) ≈ 5.67826 W/(m²·K), 1 ft²·°F/BTU ≈ 0.176096 m²·K/W.