How many tons of AC do I need for a room?

A standard 12 by 12 foot bedroom (144 sq ft) usually needs about 1.5 tons of cooling. This calculator adjusts that baseline for ceiling height, sun exposure, occupancy and appliances to give a more accurate figure.

What is a ton of cooling?

One ton of cooling equals 12,000 BTU per hour. It is the standard unit air-conditioner capacity is measured in. A 1.5 ton AC delivers 18,000 BTU per hour.

AC / HVAC Cooling Load Calculator — How Many Tons AC Do You Need?

Enter your space

Room type

Length ft

Width ft

Ceiling height ft

People in room

Sun exposure

Extra heat sources kitchen, servers, machines

Recommended AC capacity

1.5 ton

18,000 BTU / hour

Floor area144 sq ft

Room volume1,440 cu ft

Base cooling need— BTU

Suggested AC units1 × 1.5 ton

Get a proper HVAC design+880 1886-684876

This is a quick estimate using standard cooling-load rules of thumb. For factories, ducted systems or precise sizing, a full HVAC load calculation (ASHRAE method) is recommended — that is a service ClickBit Digital provides.

How to size an air conditioner

Choosing the right AC size matters more than most people think. An undersized unit runs non-stop, never cools properly and burns electricity. An oversized unit cools too fast, switches off before it removes humidity, and leaves the room cold but clammy. The goal is to match the cooling capacity to the actual heat load of your space.

Cooling capacity is measured in BTU per hour or in tons, where one ton equals 12,000 BTU per hour. A typical bedroom in Bangladesh needs somewhere between 1 and 1.5 tons, but the real number depends on room size, ceiling height, how many people use it, how much sun hits it, and whether there are heat-producing appliances inside.

What this calculator accounts for

Floor area and ceiling height — bigger volume means more air to cool.
Room type — shops and factories carry more heat load than bedrooms.
Occupancy — every person adds roughly 500–600 BTU of body heat.
Sun exposure — a west-facing glass room needs noticeably more cooling.
Extra heat sources — kitchens, servers and machinery push the load up.

When you need a professional HVAC design

A rule-of-thumb calculator like this is perfect for picking a home or office AC. But for commercial buildings, factories, ducted central systems or anything with strict comfort and energy targets, you need a proper load calculation that accounts for wall materials, insulation, air changes and local climate data. ClickBit Digital designs HVAC systems end to end — load calculation, duct layout and equipment selection.

How many tons of AC for a 12×12 room?

A standard 12 by 12 foot bedroom (144 sq ft) usually needs about 1.5 tons of cooling. If the room is very sunny, has many people or sits under a hot roof, round up. This calculator gives you the adjusted figure.

What does 1 ton AC mean?

One ton of air-conditioning removes 12,000 BTU of heat per hour. The name comes from the amount of heat needed to melt one ton of ice in a day. A 1.5 ton AC delivers 18,000 BTU per hour.

Is a bigger AC always better?

No. An oversized AC cools the air fast but shuts off before pulling out humidity, leaving the room cold and damp, and it wears out faster from short cycling. Correct sizing is more comfortable and cheaper to run.