Underfloor Radiant Heating Calculator

How to use

1. Select heating system type: electric cable or hydronic (water-based) tubing.
2. Enter total room dimensions and surface area.
3. Define net heated floor area by subtracting permanent cabinetry and fixtures.
4. Set design heat density (Watts per square meter or BTU/sq ft).
5. Specify pipe spacing interval or heating mat specifications.
6. View computed electrical capacity, total circuit wattage, and pipe length.

What Does the Radiant Floor Heating Calculator Compute?

Net heating surface: floor space unobstructed by furniture and sanitary ware.

System capacity: total heating output (kW) required to achieve comfort levels.

Tubing footage: total linear meters of PEX pipe based on loop pitch.

Equipment pricing: estimated capital outlay for manifolds, actuators, and thermostats.

Sample Capacity Calculation

For a 20 m² room with 12 m² net heated area designed at 150 W/m²: total system capacity is 1800 Watts (1.8 kW).