Insulation & comfort

R-Value Converter

Your measurements : thermal resistance r (si). Your estimate : thermal resistance r, r-value (us), thermal transmittance u.

Your measurements

How the calculation works

R-Value Converter

R (US) = R (SI) × 5.678263; U = 1 / R (SI)

Before you order

  • This is a rough planning estimate. Choose the W/m³ assumption for your situation; climate, insulation, air leakage and glazing can change the load. A professional heat-loss or cooling-load calculation is needed for final equipment selection.
  • Use the coverage, yield and dimensions printed on your product. Waste allowance is adjustable; real cuts and site conditions may change the order.

Worked example

Thermal resistance R (SI)
3 m2K/W

Thermal resistance R 3 m2K/W

R-value (US) 17.03 h·ft²·°F/BTU

Keep planning

My project

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