Radiant Floor Heating Calculator
Calculate in-floor radiant heating cost, coverage, and energy use for electric or hydronic systems.
Results
Visualization
How It Works
Radiant floor heating warms the floor surface from below. Electric mats are best for small areas (bathrooms); hydronic systems are more efficient for whole-house heating.
The Formula
Heatable Area = Room Area x 85% (subtract cabinets, fixtures) | Watts = Heatable Area x 12 W/sqft
Variables
- Heatable Area — 85% of room area (furniture and fixtures block the rest)
- Wattage — 12 watts per sq ft is standard for electric systems
- Operating Cost — kW x hours/day x days x electricity rate
Example
100 sq ft bathroom: 85 sq ft heatable. Electric mat: $1,020 materials + $150 thermostat + $255 labor = $1,425. Monthly cost: ~$32.
Tips
- Tile and stone are the best conductors — they feel warmest underfoot.
- Electric mats are DIY-friendly — embed in thinset under tile.
- Always install a programmable thermostat with floor temperature sensor.
- Radiant heat under laminate requires the manufacturer to approve it (check warranty).
- Hydronic systems cost more upfront but 40% less to operate than electric.