Texas home with outdoor AC unit during extreme summer heat

What Size AC Do I Need in Texas? (BTU & Tonnage Guide for Extreme Heat – 2026)

Texas summers put far more stress on an air conditioner than many homeowners expect. In much of the state, long stretches of intense heat combine with humidity, strong sun exposure, and heavy attic heat gain. Because of that, AC sizing in Texas usually requires more cooling capacity than the same house would need in a cooler state.

If you are asking what size AC do I need in Texas, the short answer is that most homes should be sized closer to 25 to 30 BTU per square foot, not the lower ranges often used in mild climates.

Quick Answer

Most Texas homes need about 25–30 BTU per square foot.

That usually works out to:

1,500 sq ft → 37,500–45,000 BTU (about 3–3.5 tons)
2,000 sq ft → 50,000–60,000 BTU (about 4–5 tons)
2,500 sq ft → 62,500–75,000 BTU (about 5–6 tons)

In hotter and more humid parts of Texas, it is usually safer to lean toward the upper end of the tonnage range.

If you need the basics first, read What Is BTU in Air Conditioning? and What Is a Ton in HVAC?.

Why AC sizing in Texas is different

Texas is not a mild-climate state where a simple rule of thumb always works. In many areas, cooling systems have to deal with:

long hot summers
extended 95°F to 105°F outdoor temperatures
high humidity in many regions
strong afternoon sun
heavy attic heat load

That means a home in Texas often needs more cooling capacity than the same-size home in a northern or coastal climate.

Texas is not one climate zone

The right AC size depends heavily on where you are in the state. Heat load in Houston is not the same as heat load in Dallas or El Paso.

North Texas (Dallas–Fort Worth)

North Texas gets long hot summers, frequent 95°F+ days, and moderate humidity. Homes in this region often need around 25–27 BTU per square foot.

A typical 2,000 sq ft home in this area often lands around 4 to 4.5 tons.

Gulf Coast (Houston, Galveston)

This is one of the toughest cooling environments in Texas because humidity stays high for long periods. In these areas, many homes need around 27–30 BTU per square foot.

A 2,000 sq ft home in Houston often needs about 4.5 to 5 tons.

Humidity makes a major difference because the system is not only removing heat. It is also removing moisture.

Central Texas (Austin, San Antonio)

Central Texas usually falls in the middle, with strong summer heat and mixed humidity. A practical estimate is often around 26–28 BTU per square foot.

That puts many 2,000 sq ft homes in the 4 to 4.5 ton range.

West Texas (El Paso)

West Texas is hot, but much drier. Because humidity is lower, cooling load can be slightly lower than Gulf Coast areas even when outdoor temperatures are very high.

Many homes in this part of Texas fall closer to 24–26 BTU per square foot.

Texas AC size chart

Home Size	BTU Range	Recommended Tonnage
1,200 sq ft	30,000–36,000	2.5–3 tons
1,500 sq ft	37,500–45,000	3–3.5 tons
1,800 sq ft	45,000–54,000	3.5–4.5 tons
2,000 sq ft	50,000–60,000	4–5 tons
2,500 sq ft	62,500–75,000	5–6 tons
3,000 sq ft	75,000–90,000	6–7.5 tons

For home-size-specific guides, see:

Real example: 2,000 sq ft home in Houston

Let’s say you are estimating a 2,000 sq ft house in a hot and humid part of Texas.

2,000 × 28 BTU = 56,000 BTU

56,000 ÷ 12,000 = 4.6 tons

That puts the recommended range at about 4.5 to 5 tons.

If you tried to cool that same home with only a 3.5 ton unit, the system might:

run constantly
struggle in late afternoon heat
increase energy bills
place extra strain on the compressor

For those warning signs, read Undersized AC Symptoms and Is My AC Too Small?.

What happens if you oversize in Texas?

Texas heat makes many homeowners want to go as large as possible. That can be a mistake, especially in humid parts of the state.

An oversized AC may:

cool too quickly
shut off before removing enough moisture
leave the air feeling sticky
increase mold or mildew risk over time

This is especially common in Houston-area climates, where humidity control is just as important as temperature reduction.

For more on that, read Oversized AC Symptoms and AC Short Cycling Explained.

Two-story homes in Texas need special attention

Many Texas homes are two-story suburban layouts, and these often have a recurring problem: the upstairs stays hotter than the downstairs, even when the total system size looks reasonable on paper.

That usually happens because:

heat rises
upper floors trap warm air
return ducts are too limited
airflow between floors is unbalanced

In homes over about 2,200 sq ft, many HVAC professionals start considering:

dual systems
zoned HVAC setups
two-stage or variable-speed equipment

That can work better than installing one oversized single system and hoping it solves everything.

You can compare against the broader national chart here: AC Size Chart.

What SEER rating makes sense in Texas?

Because Texas cooling seasons can last 7 to 9 months in many areas, efficiency matters more here than in cooler states.

A practical rule is:

minimum: SEER 16
better target: SEER 17–19

Higher-SEER equipment costs more up front, but in a state with long cooling seasons, it can lower electricity costs enough to matter.

For more on that, read SEER Rating Explained and AC Installation Cost Guide.

Should you rely on an online estimate in Texas?

An online BTU estimate is helpful for getting into the right range, but Texas is one of the places where guessing can get expensive fast.

A proper Manual J load calculation looks at:

window exposure
insulation quality
attic heat gain
duct losses
orientation
local weather data

That matters because two Texas homes with the same square footage can need different equipment sizes based on layout and exposure alone.

For the full sizing framework, read Air Conditioner Sizing Guide.

Bottom line

If you are asking what size AC do I need in Texas, the safest general rule is to use 25 to 30 BTU per square foot and then adjust upward for humidity, ceiling height, sun exposure, and two-story layouts.

In general:

1,500 sq ft → about 3 to 3.5 tons
2,000 sq ft → about 4 to 5 tons
2,500 sq ft → about 5 to 6 tons

The goal is not just maximum power. It is balanced cooling, humidity control, and a system that can survive Texas summers without wasting energy or wearing out early.

What Size AC Do I Need in Texas? (BTU & Tonnage Guide)