BTU Calculator - calculatorsee.com


BTU Calculator

Calculate required British Thermal Units (BTU/hr) and AC cooling tonnage based on room dimensions, ceiling height, insulation, and sun exposure.

Calculator Inputs

ft
Room length.
ft
Room width.
ft
Ceiling height.
Solar heat gain.

Calculated Results

Recommended Cooling Capacity
8,000 BTU / hour (0.67 Tons)
Air Conditioner Tonnage 0.67 Tons AC
Room Surface Area 300.0 sq ft
Room Air Volume 2,400.0 cu ft
Values calculate live as you adjust inputs.

About BTU Calculator

Calculates the thermal cooling and heating capacity in British Thermal Units (BTU per hour) needed to condition an interior space.

What is BTU Calculator?

Calculates the thermal cooling and heating capacity in British Thermal Units (BTU per hour) needed to condition an interior space.

How to Use This Calculator

  1. Enter room length, width, and ceiling height.
  2. Select sunlight exposure.
  3. Read recommended air conditioner BTU rating.

The Mathematical Formula & Variables

Base BTU = Area (sq ft) * 25 * Sun Factor * (Ceiling / 8); Tons = BTU / 12,000

Step-by-Step Worked Example

Scenario: 20 ft x 15 ft room with 8 ft ceilings and standard sun.

  1. Area = 20 * 15 = 300 sq ft.
  2. Base BTU = 300 * 25 = 7,500 BTU/hr.
  3. Recommend 8,000 BTU/hr unit (0.67 Tons).

Result: 8,000 BTU/hr

Frequently Asked Questions

How many BTUs are in 1 Ton of air conditioning?

One ton of refrigeration equals exactly 12,000 BTU/hour of heat removal.