Let’s Talk Size—Because When It Comes to AC, It Definitely Matters
If your air conditioner is too small, it’ll run constantly and struggle to cool your home. Too big? It’ll short-cycle, wasting energy and creating uncomfortable humidity swings. The sweet spot is choosing a system that matches your home’s exact cooling load.
Samantha’s Short and Sweet Sizing Formula
As a general rule of thumb:
👉 You need about 20 BTUs of cooling per square foot of living space.
But that’s just a starting point. Let’s do the math:
| Square Footage | Estimated Tonnage |
|---|---|
| 600–1,000 sq ft | 1.5 tons |
| 1,000–1,300 sq ft | 2.0 tons |
| 1,300–1,600 sq ft | 2.5 tons |
| 1,600–1,900 sq ft | 3.0 tons |
| 1,900–2,200 sq ft | 3.5 tons |
| 2,200–2,600 sq ft | 4.0 tons |
| 2,600–3,200 sq ft | 5.0 tons |
💡 Want to plug in your own numbers? Try the BTU Calculator by Room Size – PickHVAC
But It’s Not Just About Square Footage…
A real sizing calculation (called a Manual J Load Calculation) also factors in:
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Your climate zone
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Window size & direction
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Ceiling height
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Home insulation
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Number of people
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Heat from appliances
🔍 Learn more from:
📘 Manual J Load Calculation Explained – Energy Vanguard
Oversized AC: What Could Go Wrong?
I get it—it’s tempting to “go big or go home,” especially in a hot climate. But oversizing your AC can lead to:
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Short cycling: Constant starts and stops that wear out components.
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Poor humidity control: Your home might feel cool but clammy.
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Higher energy bills: You’re paying for more cooling power than you need.
Real-World Tip from a Smart Shopper
When we replaced our unit two years ago, I used an online tonnage calculator and got a second opinion from an HVAC tech. Our 1,800 sq ft home landed perfectly with a 3 Ton, 14.5 SEER2 R-32 Goodman System, like this one:
🔗 Goodman 3 Ton 14.5 SEER2 R-32 Air Conditioner and Air Handler
It’s been smooth, cool, and quiet ever since.
Samantha’s Smart Shopper Summary
If you're buying an AC system, sizing is the most important first step. Don’t guess—use a BTU calculator, consider Manual J insights, and when in doubt, ask for a second opinion. A properly sized system:
✅ Lasts longer
✅ Costs less to run
✅ Keeps your family more comfortable
Because peace of mind isn’t about buying the biggest—it’s about buying what’s right.
