Convert Tog to m²·h·°C/kcal

Formula

m²·h·°C/kcal = tog × 0.1163

or m²·h·°C/kcal = tog ÷ 8.59845227859

Derivation from SI units:

• 1 tog = 0.1 m²·K/W.
• 1 m²·h·°C/kcal_IT = 3600 s ÷ 4186.8 J × m²·K ≈ 0.85985 m²·K/W.
• 1 tog = 0.1 m²·K/W ÷ 0.859845227859 m²·K/W per m²·h·°C/kcal = 0.1163 m²·h·°C/kcal

Both units are defined exactly, so the factor is exact. Tog definition: tog; Square Metre Hour Degree Celsius per Kilocalorie definition: square metre hour degree Celsius per kilocalorie.

Worked examples

1. A reading of 4.5 tog converts to 0.52335 m²·h·°C/kcal.
   4.5 tog × 0.1163 = 0.52335 m²·h·°C/kcal
2. A value of 10.5 tog is 1.22115 m²·h·°C/kcal.
   10.5 tog × 0.1163 = 1.22115 m²·h·°C/kcal

Where it's used

Tog are used for duvet and baby sleeping-bag ratings (BS 5335), while square metre hour degree Celsius per kilocalorie appear in older building-physics texts and IS codes. 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

Frequently asked questions

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, "calorie_IT".

Last reviewed: 2026-10-15. Factors are stored exactly and computed with 50-digit decimal arithmetic. See how we verify conversion factors.