Use this engineering calculation for a transparent preliminary estimate or independent arithmetic check when geometry, materials, loads, operating conditions, and units are defined consistently.

First Thickness Meters (m)

Required number input.

First Conductivity Watts Per Meter Kelvin (W/(m·K))

Required number input.

Second Thickness Meters (m)

Required number input.

Second Conductivity Watts Per Meter Kelvin (W/(m·K))

Required number input.

Area-normalized thermal resistance of two plane solid layers in series, d1/k1+d2/k2; excludes film resistances. The tool evaluates the supplied inputs together and returns the named outputs below; it does not infer omitted operating conditions or change the units shown.^[1]

Area Resistance Square Meter Kelvin Per Watt (m²K/W)

The resulting area resistance square meter kelvin per watt returned as a number.

• Heat-transfer estimates depend on geometry, contact resistances, radiation, convection regime, temperature-dependent properties, fouling, phase change, and boundary conditions. Tabulated coefficients and COP values are operating-condition specific.
• Use finite inputs in the displayed units and preserve more precision than the final presentation requires. Independently verify safety-critical, financial, compliance, or production decisions.

Check assumptions against drawings, measurements, current material data, and the applicable design code. Apply required load combinations and safety factors, then obtain qualified review and testing for consequential designs.

• Thermal Resistance Series

  Total thermal resistance of two one-dimensional heat-flow layers connected in series at the same heat rate.

• Overall Heat Transfer Coefficient

  Area-based overall heat-transfer coefficient from three supplied thermal resistances per unit area in series.

• Moment Inertia Circle

  Centroidal second moment of area of a solid circular section about any in-plane diameter: πd⁴/64.