Convert US R-Value to Tog (ft2 F h/BTU to tog)
1 US R-value (ft²·°F·h/BTU) = 1.761101837 tog. 1 tog = 0.5678263341 ft²·°F·h/BTU. Example: 15 ft²·°F·h/BTU = 15 × 1.761101837 = 26.41652755 tog.
Also searched as US R-value to tog, US R-value in tog, US R-value into tog, ft2 F h/BTU to tog, ft2 F h/BTU in tog, ft2 F h/BTU into tog, ft2 F h/BTU to tog converter and how many tog in a US R-value.
1 ft²·°F·h/BTU = 1.761101837 tog
Type in either box. Scientific notation works: 1.5e-3.
Converting a list? Use the bulk R (US) to tog converter to paste a column from Excel.
How to Convert US R-Value to Tog
- 1 ft²·°F·h/BTU = 1.761101837 tog
- 1 tog = 0.5678263341 ft²·°F·h/BTU
- Example: convert 15 ft²·°F·h/BTU to tog: 15 ft²·°F·h/BTU = 15 × 1.761101837 tog = 26.41652755 tog
Formula
tog = ft²·°F·h/BTU × 1.761101836823
Derivation from SI units:
- 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.
- 1 ft²·°F·h/BTU = 0.1761101836823 m²·K/W ÷ 0.1 m²·K/W per tog = 1.761101836823 tog
Both units are defined exactly, so the factor is exact. US R-Value definition: US R-value; Tog definition: tog.
Worked examples
- A reading of 11 ft²·°F·h/BTU converts to 19.37212021 tog.
11 ft²·°F·h/BTU × 1.761101837 = 19.37212021 tog - A value of 21 ft²·°F·h/BTU is 36.98313857 tog.
21 ft²·°F·h/BTU × 1.761101837 = 36.98313857 tog
US R-Value to Tog conversion table
| US R-Value (ft²·°F·h/BTU) | Tog |
|---|---|
| 1 ft²·°F·h/BTU | 1.761101837 tog |
| 3 ft²·°F·h/BTU | 5.28330551 tog |
| 5 ft²·°F·h/BTU | 8.805509184 tog |
| 11 ft²·°F·h/BTU | 19.37212021 tog |
| 13 ft²·°F·h/BTU | 22.89432388 tog |
| 19 ft²·°F·h/BTU | 33.4609349 tog |
| 21 ft²·°F·h/BTU | 36.98313857 tog |
| 30 ft²·°F·h/BTU | 52.8330551 tog |
| 38 ft²·°F·h/BTU | 66.9218698 tog |
| 49 ft²·°F·h/BTU | 86.29399 tog |
Where it's used
US R-Value are used for US insulation labels (R-13, R-19, R-38), while tog appear in duvet and baby sleeping-bag ratings (BS 5335). Both measure thermal resistance per unit area (insulation R-value), so the conversion is a fixed factor.
US R-Value to other thermal resistance (r-value) units
| Conversion | 1 ft²·°F·h/BTU equals |
|---|---|
| R (US) to tog | 1.761101837 tog |
| R (US) to RSI | 0.1761101837 m²·K/W |
| R (US) to clo | 1.136194733 clo |
| R (US) to square metre hour degree Celsius per kilocalorie | 0.2048161436 m²·h·°C/kcal |
Frequently asked questions
How many tog are in 1 US R-value?
1 ft²·°F·h/BTU = 1.761101837 tog.
How do I convert US R-value to tog?
Multiply the value in ft²·°F·h/BTU by 1.761101837. For example, 15 ft²·°F·h/BTU × 1.761101837 = 26.41652755 tog.
Is the ft²·°F·h/BTU to tog 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
- 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".
- The International System of Units (SI), 9th edition (SI Brochure), Bureau International des Poids et Mesures , Table 4 (derived units with special names).
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 US R-Value to Tog (ft2 F h/BTU to tog). Retrieved October 29, 2026, from https://scientificconverters.com/thermal-resistance/r-value-to-tog/
IEEE
Scientific Converters, "Convert US R-Value to Tog (ft2 F h/BTU to tog)," scientificconverters.com. Accessed: Oct. 29, 2026. [Online]. Available: https://scientificconverters.com/thermal-resistance/r-value-to-tog/