BTUcalc
Free BTU & AC size calculator that runs 100% in your browser.
Runs locally in your browser — no upload, no trackingMain Calculator
BTU & AC Size Calculator
Estimate the cooling and heating BTU your room needs from area, ceiling, occupants, sun, insulation and climate zone. Runs 100% in your browser.
By room size
BTU Calculator for a 10×10 Room
A 10×10 room is 100 sq ft. Estimate the cooling BTU and the right AC size here, with climate and sun adjustments.
BTU Calculator for a 12×12 Room
A 12×12 room is 144 sq ft. Estimate the cooling BTU and the right AC size here, with climate and sun adjustments.
BTU Calculator for a 15×15 Room
A 15×15 room is 225 sq ft. Estimate the cooling BTU and the right AC size here, with climate and sun adjustments.
BTU Calculator for a 20×20 Room
A 20×20 room is 400 sq ft. Estimate the cooling BTU and the right AC size here, with climate and sun adjustments.
BTU Calculator for a 200 sq ft Room
A 200 sq ft room is 200 sq ft. Estimate the cooling BTU and the right AC size here, with climate and sun adjustments.
BTU Calculator for a 300 sq ft Room
A 300 sq ft room is 300 sq ft. Estimate the cooling BTU and the right AC size here, with climate and sun adjustments.
BTU Calculator for a 500 sq ft Room
A 500 sq ft room is 500 sq ft. Estimate the cooling BTU and the right AC size here, with climate and sun adjustments.
BTU Calculator for a 800 sq ft Room
A 800 sq ft room is 800 sq ft. Estimate the cooling BTU and the right AC size here, with climate and sun adjustments.
BTU Calculator for a 1000 sq ft Room
A 1000 sq ft room is 1000 sq ft. Estimate the cooling BTU and the right AC size here, with climate and sun adjustments.
BTU Calculator for a 1200 sq ft Room
A 1200 sq ft room is 1200 sq ft. Estimate the cooling BTU and the right AC size here, with climate and sun adjustments.
By room type
BTU Needed for a Bedroom
How many BTU does a bedroom need? Estimate the AC size for this room type with sun, insulation and climate adjustments.
BTU Needed for a Living Room
How many BTU does a living room need? Estimate the AC size for this room type with sun, insulation and climate adjustments.
BTU Needed for a Kitchen
How many BTU does a kitchen need? Estimate the AC size for this room type with sun, insulation and climate adjustments.
BTU Needed for a Garage
How many BTU does a garage need? Estimate the AC size for this room type with sun, insulation and climate adjustments.
BTU Needed for a Basement
How many BTU does a basement need? Estimate the AC size for this room type with sun, insulation and climate adjustments.
Conversions
BTU to Tons Converter
Convert BTU to tons of cooling and back. One ton equals 12,000 BTU — see what size air conditioner your BTU number means.