Boiler Capacity Calculator
Calculate the correct boiler size for your home or building. Estimate heating requirements, efficiency ratings, and annual fuel costs.
Step 1: Building Details
Heating Capacity Guide
Typical heating requirements: 25-35 BTU per sq ft for mild climates, 35-45 BTU for moderate, 45-60 BTU for cold climates.
Step 2: Boiler Specifications
Efficiency Guide
AFUE (Annual Fuel Utilization Efficiency) measures boiler efficiency. Modern condensing boilers: 90-98%, older boilers: 70-85%.
Boiler Capacity Estimate
Required Boiler Capacity
Recommended Boiler Specifications
| Specification | Value | Unit | Notes |
|---|
Sizing Guidelines
Proper boiler sizing prevents short cycling (too large) or inadequate heating (too small). Consider zoning for larger buildings and future expansion.
Annual Operating Cost Breakdown
Heating Load Calculation Formula
BTU/h = Area × Heating Factor × Climate Factor × Insulation Factor
Heating factor: 30-60 BTU/sq ft. Add 10-20% for hot water. Divide by efficiency to get actual fuel requirement.
Need Professional Boiler Installation?
Connect with our HVAC experts for professional boiler sizing, installation, and maintenance services. Get free quotes from certified heating engineers.
Get Professional Quote