Heat Pump Sizing Calculator
Estimate preliminary heat-pump capacity from floor area, design-load intensity and an editable sizing adjustment. Enter project-specific values and review every assumption before using the estimate.
Fill in the required fields to see your result.
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The primary result shows the main estimated capacity, current, airflow, metric or business value. Supporting outputs expose intermediate calculations.
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How to Use This Calculator
Enter the requested values using the units shown. Confirm that all inputs describe the same period, system or project.
Formula & Methodology
The calculator applies the displayed arithmetic or engineering formula directly to the entered values without silently adding hidden assumptions.
Worked example
Cold-weather output depends on the selected model’s performance data. Verify capacity at the actual outdoor design temperature.
Results may omit equipment-specific starting current, conductor temperature, derating, local codes, climate design data, duct losses, static pressure, infiltration and building-envelope details.
Educational preliminary estimate only. Not an electrical design, HVAC load calculation, permit document or code-compliance determination. Work on electrical and mechanical systems should be verified by qualified professionals.
Related Guides
- Heat Pump Sizing Guide: How to Choose the Right TonnageSize a heat pump correctly for heating and cooling by climate zone. Covers the Manual J approach, heating vs. cooling dominant sizing, and cold-climate heat pump performance.
- BTU Calculator: How to Size an Air Conditioner or Heater for Any RoomCalculate the BTU capacity you need to cool or heat any room. Covers the 20 BTU per sq ft baseline, adjustment factors for climate and insulation, and common sizing mistakes.
- Electrical Load Calculator: How to Estimate Home Panel and Circuit LoadsLearn to calculate your home's electrical load for panel sizing, service entry, and circuit planning. Covers NEC Standard Method, demand factors, and what drives panel capacity.
- Mini Split Sizing Guide: BTU, SEER, and the Right Size for Your SpaceSize a mini split for any room with the BTU-per-sq-ft method. Covers available mini split sizes, SEER ratings, single-zone vs. multi-zone systems, and installation requirements.
- How Manual D Friction Rate and Duct Sizing WorksUnderstand how ACCA Manual D duct design works — how available static pressure and friction rate determine duct sizes, and how to calculate CFM requirements for each room.
Frequently Asked Questions
- What does the Heat Pump Sizing Calculator calculate?
- Estimate preliminary heat-pump capacity from floor area, design-load intensity and an editable sizing adjustment.
- Are the results guaranteed or code-compliant?
- No. It is a preliminary educational estimate and does not establish code compliance, equipment suitability, permit approval or installation safety.
- Can I change the assumptions?
- Yes. The calculator exposes the main design, operating or financial assumptions so you can replace examples with project-specific values.
- Should the result be independently verified?
- Yes. Verify the result with applicable codes, manufacturer data, approved load calculations and a qualified electrician, engineer or HVAC professional.
Last updated 7/21/2026