How to use the insulation r-value to u-value calculator
Convert an insulation R-value into a U-value and find the heat loss through a wall. Enter thermal resistance r-value, area, temperature difference in the fields above; the u-value, heat loss are computed instantly and plotted on the chart so you can see how the answer changes.
Common searches this calculator answers include “R value to U value”, “wall insulation heat loss”, “insulation thermal resistance”, “calculate insulation r-value to u-value”, “find u-value”.
Formula
Variables
- R — Thermal resistance R-value (m²·K/W)
- A — Area (m²)
- dT — Temperature difference (K)
Worked example
With thermal resistance r-value = 3.5 m²·K/W, area = 10 m², temperature difference = 25 K, the calculator gives u-value ≈ 0.2857143 W/(m²·K); heat loss ≈ 71.42857 W.
Frequently asked questions
What is the insulation r-value to u-value calculator used for?
Convert an insulation R-value into a U-value and find the heat loss through a wall. It helps with questions such as “R value to U value”, “wall insulation heat loss”, “insulation thermal resistance”.
What is the formula for the insulation r-value to u-value calculation?
U-value (W/(m²·K)) = 1 / R. Heat loss (W) = [U-value] × A × dT. Here R is thermal resistance r-value (m²·K/W), A is area (m²), dT is temperature difference (K).
What inputs do I need for the insulation r-value to u-value calculator?
You need thermal resistance r-value in m²·K/W, area in m², temperature difference in K. Each field is pre-filled with a typical example so you can see how the result responds as you edit the numbers.
How do I use the insulation r-value to u-value calculator?
Type values into the input fields. Results and the chart update instantly. Use Reset to restore the example values, Copy results to paste them elsewhere, or Share to copy a link that preserves your inputs.
Is the insulation r-value to u-value result exact?
Calculations use standard formulas and double-precision arithmetic, then display about seven significant figures. Real-world measurements carry uncertainty, so treat results as estimates unless your inputs are exact.