Convert Tog to US R-Value (tog to ft2 F h/BTU)
1 tog = 0.5678263341 US R-value (ft²·°F·h/BTU). 1 ft²·°F·h/BTU = 1.761101837 tog. Example: 15 tog = 15 × 0.5678263341 = 8.517395012 ft²·°F·h/BTU.
Also searched as tog to ft2 F h/BTU, tog in ft2 F h/BTU, tog into US R-value, tog in US R-value, tog to US R-value, tog to US R-value converter and how many US R-value in a tog.
1 tog = 0.5678263341 ft²·°F·h/BTU
Type in either box. Scientific notation works: 1.5e-3.
Converting a list? Use the bulk tog to R (US) converter to paste a column from Excel.
How to Convert Tog to US R-Value
- 1 tog = 0.5678263341 ft²·°F·h/BTU
- 1 ft²·°F·h/BTU = 1.761101837 tog
- Example: convert 15 tog to ft²·°F·h/BTU: 15 tog = 15 × 0.5678263341 ft²·°F·h/BTU = 8.517395012 ft²·°F·h/BTU
Formula
ft²·°F·h/BTU = tog × 0.5678263341113
or ft²·°F·h/BTU = tog ÷ 1.761101836823
Derivation from SI units:
- 1 tog = 0.1 m²·K/W.
- 1 ft²·°F·h/BTU_IT = 0.09290304 m² × (5/9) K × 3600 s ÷ 1055.05585262 J ≈ 0.17611 m²·K/W.
- 1 tog = 0.1 m²·K/W ÷ 0.1761101836823 m²·K/W per ft²·°F·h/BTU = 0.5678263341113 ft²·°F·h/BTU
Both units are defined exactly, so the factor is exact. Tog definition: tog; US R-Value definition: US R-value.
Worked examples
- A reading of 4.5 tog converts to 2.555218504 ft²·°F·h/BTU.
4.5 tog × 0.5678263341 = 2.555218504 ft²·°F·h/BTU - A value of 10.5 tog is 5.962176508 ft²·°F·h/BTU.
10.5 tog × 0.5678263341 = 5.962176508 ft²·°F·h/BTU
Tog to US R-Value conversion table
| Tog | US R-Value (ft²·°F·h/BTU) |
|---|---|
| 0.5 tog | 0.2839131671 ft²·°F·h/BTU |
| 1 tog | 0.5678263341 ft²·°F·h/BTU |
| 2.5 tog | 1.419565835 ft²·°F·h/BTU |
| 4.5 tog | 2.555218504 ft²·°F·h/BTU |
| 7.5 tog | 4.258697506 ft²·°F·h/BTU |
| 9 tog | 5.110437007 ft²·°F·h/BTU |
| 10.5 tog | 5.962176508 ft²·°F·h/BTU |
| 12 tog | 6.813916009 ft²·°F·h/BTU |
| 13.5 tog | 7.665655511 ft²·°F·h/BTU |
| 15 tog | 8.517395012 ft²·°F·h/BTU |
Where it's used
Tog are used for duvet and baby sleeping-bag ratings (BS 5335), while US R-value appear in US insulation labels (R-13, R-19, R-38). Both measure thermal resistance per unit area (insulation R-value), so the conversion is a fixed factor.
Tog to other thermal resistance (r-value) units
| Conversion | 1 tog equals |
|---|---|
| tog to R (US) | 0.5678263341 ft²·°F·h/BTU |
| tog to RSI | 0.1 m²·K/W |
| tog to clo | 0.6451612903 clo |
| tog to square metre hour degree Celsius per kilocalorie | 0.1163 m²·h·°C/kcal |
Frequently asked questions
How many US R-value are in 1 tog?
1 tog = 0.5678263341 ft²·°F·h/BTU.
How do I convert tog to US R-value?
Multiply the value in tog by 0.5678263341, or divide it by 1.761101837. For example, 15 tog × 0.5678263341 = 8.517395012 ft²·°F·h/BTU.
Is the tog to ft²·°F·h/BTU conversion exact?
Yes. Both units are defined exactly, so the ratio is exact; its decimal form does not terminate and is shown here to 10 significant figures (more with the precision selector).
Sources
- The International System of Units (SI), 9th edition (SI Brochure), Bureau International des Poids et Mesures , Table 4 (derived units with special names).
- Guide for the Use of the International System of Units (SI), NIST Special Publication 811, 2008 Edition, National Institute of Standards and Technology , Appendix B.8, "degree Fahrenheit hour square foot per British thermal unit_IT".
Last reviewed: . Factors are stored exactly and computed with 50-digit decimal arithmetic. See how we verify conversion factors.
Cite this page
APA
Scientific Converters. (2026, October 15). Convert Tog to US R-Value (tog to ft2 F h/BTU). Retrieved October 29, 2026, from https://scientificconverters.com/thermal-resistance/tog-to-r-value/
IEEE
Scientific Converters, "Convert Tog to US R-Value (tog to ft2 F h/BTU)," scientificconverters.com. Accessed: Oct. 29, 2026. [Online]. Available: https://scientificconverters.com/thermal-resistance/tog-to-r-value/