AC Tonnage Calculator
Free AC tonnage calculator. Enter room size, sun exposure and kitchen to get the cooling capacity in BTU, tons and kW for the right air conditioner or mini-split size.
About This Free Online AC Tonnage Calculator
Our free AC tonnage calculator helps you size an air conditioner or mini-split correctly. Enter the room length and width, whether it is sunny or on the top floor, whether it includes a kitchen, and the number of occupants, and the tool works out the cooling load in BTU per hour, the tonnage (12,000 BTU per ton) and the thermal kilowatts. It factors in sun exposure, kitchen heat and extra people so you avoid an undersized or oversized unit. Everything runs in your browser — perfect for homeowners and HVAC planning.
Features of Our AC Tonnage Calculator
- Cooling load in BTU/hr from room area
- Adjustments for sun exposure, kitchen and occupants
- Tonnage and thermal kW for sizing the unit
- Comfortable, code-friendly results rounded to the nearest 1,000 BTU
- Works for single rooms, additions and mini-splits
- 100% client-side and private — instant results, no signup
How to Use the AC Tonnage Calculator
Using this tool is simple and requires no signup or registration. Follow these steps:
- Enter the room length and width in feet.
- Tick if the room is sunny or on the top floor, and if it includes a kitchen.
- Set the number of usual occupants.
- Read off the BTU, tons and kW you need.
Frequently Asked Questions About AC Tonnage Calculator
How many BTU do I need per square foot?
A common rule is about 20 to 25 BTU per square foot of living space, then adjust up for sun, kitchens and extra occupants. A sunny or top-floor room adds about 10%, a kitchen adds 4,000 BTU, and each person beyond two adds 600 BTU. The calculator applies all of these.
What does AC tonnage mean?
One ton of cooling equals 12,000 BTU per hour. A 2-ton unit delivers 24,000 BTU/hr. To convert your BTU result to tons, divide by 12,000 — the calculator shows both.
What happens if my AC is too big?
An oversized AC short-cycles: it cools the room fast but does not run long enough to remove humidity, leaving a cold but clammy space. Sizing to the actual load (this calculator) avoids that and saves energy.
Do I count a kitchen or extra people?
Yes. A kitchen adds heat from appliances (about 4,000 BTU), and each occupant beyond the first two adds roughly 600 BTU of body heat. Tick the boxes and the calculator includes them.
Is this AC calculator free?
Yes, completely free with no signup. All estimates run in your browser — nothing is uploaded or tracked.
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