AC Size (BTU) Calculator for Ohio Homes
Get a quick estimate of the air conditioner size your home needs, in BTUs and tons.
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0 tons
0 BTU/hr
A typical —-ton system installed costs about —.
Price ranges come from HomeAdvisor / Angi cost guides, Fixr cost guides, NerdWallet home improvement costs, adjusted for Ohio and the Midwest (last reviewed October 2026). They are for planning only; your actual quote depends on your home and local pricing.
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How to use this calculator
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- 2Save your estimate
- 3Compare local pros
How this AC size calculator works
We start at 20 BTU per square foot, then adjust for climate (−10% to +30%), insulation (±15%), sun exposure (±10%) and add 600 BTU for each person beyond two. The result is rounded up to the nearest half ton, which is how systems are sold.
Quick sizing chart for Northwest Ohio homes
Average insulation and sun, two to four people. One ton equals 12,000 BTU per hour.
| Cooled area | Typical size |
|---|---|
| 600–1,000 sq ft | 1.5 tons (18,000 BTU) |
| 1,000–1,400 sq ft | 2 tons (24,000 BTU) |
| 1,400–1,800 sq ft | 2.5–3 tons (30,000–36,000 BTU) |
| 1,800–2,400 sq ft | 3.5–4 tons (42,000–48,000 BTU) |
| 2,400–3,000 sq ft | 4–5 tons (48,000–60,000 BTU) |
Oversizing is the most common mistake: a unit that's too big short-cycles, wastes power and leaves humid Ohio summers feeling clammy. A contractor's Manual J load calculation is the final word.
Frequently asked questions
How many BTUs do I need per square foot?
A common rule of thumb is about 20 BTU per square foot, adjusted for climate, insulation, sun exposure and occupants.
What does '1 ton' mean for an AC?
One ton of cooling equals 12,000 BTU per hour. Most homes need 1.5 to 5 tons.
Is a bigger AC better?
No. An oversized unit cools too fast, short-cycles, wastes energy and leaves humidity behind. A pro should run a Manual J load calculation before you buy.
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