Thermal Resistance (R-value) Conversion Chart

Printable thermal resistance (r-value) conversion tables for the most-used conversions. Values are exact or rounded to 6 significant figures. Free to print and share with the credit line “Scientific Converters (scientificconverters.com)”.

Download PNG chart Open the R-Value Converter (US R to RSI, m²·K/W)

R (US) to RSI

R (US) to RSI conversion chart
ft²·°F·h/BTU	m²·K/W
1	0.17611
3	0.528331
5	0.880551
11	1.93721
13	2.28943
19	3.34609
21	3.69831
30	5.28331
38	6.69219
49	8.6294

RSI to R (US)

RSI to R (US) conversion chart
m²·K/W	ft²·°F·h/BTU
0.1	0.567826
0.5	2.83913
1	5.67826
1.5	8.5174
2	11.3565
2.5	14.1957
3	17.0348
4	22.7131
5	28.3913
7	39.7478

clo to RSI

clo to RSI conversion chart
clo	m²·K/W
0.3	0.0465
0.5	0.0775
0.6	0.093
0.7	0.1085
1	0.155
1.2	0.186
1.5	0.2325
2	0.31
3	0.465
4	0.62

clo to tog

clo to tog conversion chart
clo	tog
0.3	0.465
0.5	0.775
0.6	0.93
0.7	1.085
1	1.55
1.2	1.86
1.5	2.325
2	3.1
3	4.65
4	6.2

tog to clo

tog to clo conversion chart
tog	clo
0.5	0.322581
1	0.645161
2.5	1.6129
4.5	2.90323
7.5	4.83871
9	5.80645
10.5	6.77419
12	7.74194
13.5	8.70968
15	9.67742

Source: Scientific Converters (scientificconverters.com), data version 2026-10-15. Factors from NIST SP 811 and the BIPM SI Brochure. Licence: CC BY 4.0.