Heat Pump Size Calculator
Estimate heat pump sizing from a home's floor area. Enter the conditioned square footage and the tool returns the required capacity in BTU/hr using a 30 BTU per square foot rule, rounded to the nearest 100, plus the equivalent size in refrigeration tons.
What this calculator does
The Heat Pump Size Calculator estimates your result instantly from the values you enter, using standard construction & home formulas. Estimate heat pump sizing from a home's floor area. Enter the conditioned square footage and the tool returns the required capacity in BTU/hr using a 30 BTU per square foot rule, rounded to the nearest 100, plus the equivalent size in refrigeration tons. Calculations run in your browser, so nothing you type is sent to a server, and the output is an estimate rather than a certified or official figure.
Result
About Heat Pump Size Calculator
This calculator takes a single input, the home's conditioned area in square feet, and applies a rule of thumb of roughly 30 BTU per square foot. It multiplies the area by 30, rounds the result to the nearest 100 BTU, and reports that as the required capacity.
It also divides the capacity by 12,000 to show the equivalent size in tons, since one ton of cooling equals 12,000 BTU/hr. Everything runs in your browser with no sign-up.
Formula & Mathematical Calculation
Capacity (BTU/hr) = f(Home Area (ft²))
Calculated according to standard construction formulas implemented in the calculator core.
Calculation Example
Enter a Home Area of 1,500 ft².
Capacity = round(1,500 × 30 ÷ 100) × 100 = round(450) × 100 = 45,000 BTU.
Tons = 45,000 ÷ 12,000 = 3.75 tons.
The tool shows Capacity (BTU/hr) as 45,000 BTU and Tons as 3.75 tons.
Key Benefits
- Turns a single square-footage figure into a capacity estimate in BTU/hr without any manual arithmetic
- Reports the same result in tons so you can match it against equipment rated by ton
- Rounds the capacity to the nearest 100 BTU to keep the number practical
- Runs entirely in the browser with no sign-up
How to Use this Calculator
-
Enter the home area
Type the conditioned floor area in square feet into the Home Area (ft2) field. -
Calculate
Press the Calculate button to run the 30 BTU per square foot estimate. -
Read the results
Check the Capacity (BTU/hr) box for the sizing figure and the Tons box for the equivalent tonnage.
Assumptions & Limitations
What the calculation assumes
- Every value you enter is treated as an exact, known amount.
- Any rate or interval you enter is assumed to hold for the whole period unless the form asks for it separately.
- Results use standard published formulas and account only for the values entered above.
- Rounding is applied for display; the underlying calculation uses your full precision.
- Results are returned in the same units you enter, unless the tool states the output unit.
What it does not cover
- Heat Pump Size Calculator produces a calculated result for reference and learning, not a certified or official measurement.
- Real-world outcomes differ when tolerances, rounding rules or local standards apply.
- Definitions and standards vary by region and change over time; verify the convention that applies to your case.
- Figures are only as accurate as the inputs you supply — check them before acting on the result.
- For work where the result carries real consequences, confirm it against an authoritative source.
Frequently Asked Questions
Free to use, no account needed. Calculations run in your browser, so nothing you type is sent to a server. Results are estimates — how we build and check our calculators.