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Air Conditioner Room Size Calculator

Result

Calculated result 4000 Based on the values entered.
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Air Conditioner Room Size Calculator The Air Conditioner Room Size Calculator estimates the cooling capacity (in BTU/hr) a room needs from its floor area and a BTU-per-square-foot climate factor. As a rule of thumb, rooms need roughly 20 BTU/hr per square — free online calculator.

Formula

BTU = Room Size (sq ft) × BTU per sq ft
  • Air Conditioner Room Size Calculator calculates its result from Room Size Sq Ft, Btu Per Sq Ft. It uses the formula BTU = Room Size (sq ft) × BTU per sq ft. Change any input to recalculate the result instantly.
  • The main inputs are Room Size Sq Ft, Btu Per Sq Ft. Enter them in the units and format shown in the calculator.
  • Keep measurements and project assumptions consistent before comparing or combining values.
  • Changing any input above recalculates the result with the same calculation engine used by this page.

Example: Air Conditioner Room Size

Inputs
  • Room Size Sq Ft: 200
  • Btu Per Sq Ft: 20

Using Room Size Sq Ft = 2, Btu Per Sq Ft = 3, the calculated result is 6.

Sample result: Calculating…

Frequently asked questions

What does the Air Conditioner Room Size calculate?

Air Conditioner Room Size Calculator The Air Conditioner Room Size Calculator estimates the cooling capacity (in BTU/hr) a room needs from its floor area and a BTU-per-square-foot climate factor. As a rule of thumb, rooms need roughly 20 BTU/hr per square — free online calculator.

Which values should I enter?

Enter Room Size Sq Ft, Btu Per Sq Ft using the units and format shown beside each field.

What formula does this calculator use?

The calculator uses the following relationship: BTU = Room Size (sq ft) × BTU per sq ft.

Why might my result differ from another source?

Results can differ when another source uses different units, rounding rules, conventions or assumptions. Compare the inputs and definitions before comparing results.

Does the result update automatically?

Yes. Changing an input updates the result using the same calculation engine shown on this page.

Page information

Updated: October 10, 2026