This calculator gives an estimate using a simplified formula. Actual savings vary with your home, ducts, habits and rates.
Wondering whether a new, more efficient air conditioner or heat pump will pay for itself? Enter a few numbers below and see the yearly saving.
1 ton = 12,000 BTU/hr. A typical home central system is 2–5 tons.
Current federal minimums: 13.4 SEER2 (North), 14.3 SEER2 (Southeast/Southwest). ENERGY STAR starts around 15.2 SEER2.
Defaults to the U.S. average residential rate (EIA, May 2026 data). Replace with your own utility rate for accuracy — rates range from about $0.12 to over $0.50/kWh by state.
Price difference versus a baseline code-minimum system — not the full installation cost. Leave blank to skip the payback estimate.
Estimated annual savings
kWh saved / year
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Energy use cut by
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Simple payback
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Table of Contents
What SEER2 rating is realistic to shop for?
Per the U.S. Department of Energy’s own federal-purchasing acquisition guidance for residential central air conditioners (energy.gov, updated December 2024), the current baseline federal minimum is 13.4–14.3 SEER2 depending on region, ENERGY STAR-qualified equipment sits around 15.2 SEER2, and the best widely available residential systems reach roughly 23.5 SEER2. Most homeowners land in the 15–18 SEER2 range for a practical balance of upfront cost and efficiency gain — the jump from code-minimum to ENERGY STAR captures a large share of the available savings at a relatively modest cost premium, while chasing the top of the range delivers a smaller marginal gain (see the diminishing-returns math in the guide above) for a much larger price jump.
How This SEER2 Savings Calculator Works
The math is simple. Yearly cooling energy equals the system size in BTU, times the hours it runs, divided by the SEER rating times 1,000. The calculator does that math twice, once for the old rating and once for the new one. The gap in kilowatt hours, times your electric rate, is the yearly saving.
Formula: kWh = (BTU per hour × yearly hours) ÷ (SEER × 1,000)
It also turns the saving into a percent and, if you enter the extra price of the better unit, a rough payback in years. The built-in climate hours are 3,400 for hot and humid, 1,600 for hot and dry and 1,700 for northern states. Choose custom to enter your own.
Here is where efficiency ratings are heading: higher SEER2 numbers as the baseline, plus variable-speed and heat pump systems that sip power. Federal minimums have already moved once, and more rebates tie to SEER2 and heat pump swaps.
Worked Examples
- Hot and humid, 3-ton system, SEER 10 to 16, 16 cents per kWh. Old use is about 12,240 kWh and new use about 7,650 kWh. That saves roughly 4,590 kWh, or about $734 a year. With $2,500 of extra cost, payback is near 3.4 years.
- Northern state, 3-ton system, SEER 13 to 16. Old use is about 4,708 kWh and new use about 3,825 kWh. That saves roughly 883 kWh, or about $141 a year. With the same $2,500 extra cost, payback is near 17.7 years.
Same system size, very different answer. Hours of use and the old rating decide most of the result.
SEER vs SEER2: Do Not Mix Them Up
SEER2 is the newer test, in use since 2023. It runs the unit under tougher conditions, so the same machine scores a bit lower on SEER2 than it did on the old SEER scale. If you compare an old SEER sticker with a new SEER2 number, the saving looks smaller than it really is. Compare like with like when you can, and check current federal minimums for your region.
What Makes the Estimate Better or Worse
- Size in tons or BTU. One ton is 12,000 BTU per hour. Check the nameplate on your outdoor unit.
- Real run hours. A shaded home with mild summers uses far fewer hours than a sunny home in the South.
- Your electric rate. Use the rate on your latest bill, not a national average.
- Ducts and install. Leaky ducts can eat a big share of the saving.
The downside is the sales pitch. A bigger SEER2 number costs more up front, and a payback of 15 or 20 years is a poor deal on a system that may last about as long. Savings also shrink when ducts leak, when the system is the wrong size or when the cooling season is short. Rates change, so a payback that looks fine at today’s price can look different next summer. Treat the result as a fair estimate, not a promise.
What to Do With the Number
A short payback, say under 8 to 10 years, makes a strong case for an upgrade. A long payback may still be worth it if your system is old, loud or failing. If you are unsure about size first, run the AC tonnage calculator or the BTU calculator. For the bigger picture, read the SEER2 energy savings guide. Thinking ductless? See the best mini-split air conditioners. If your current unit is not cooling at all, start with central air conditioner not cooling.
FAQ
How is the savings number calculated?
It multiplies system BTU by yearly hours, divides by SEER times 1,000 for old and new ratings, then multiplies the kilowatt hour gap by your rate.
Is a higher SEER2 always worth it?
No. Payback depends on your climate, electric rate and the extra price. Short cooling seasons stretch payback.
What is a good payback period?
Under about 8 to 10 years is a strong case. Longer can still make sense for an old or failing system.
Does this replace a contractor quote?
No. It is a quick estimate. A contractor should check ducts, size and install quality.
Final Word
Run the numbers with your own rate and climate. A fast payback is a green light, and a slow one is a reason to wait.
What comes next: more rebates, more heat pumps and more utility programs that pay for tune-ups. Run the numbers with your own rate and climate before you sign a quote.
Related Guides
Keep going with SEER2 energy savings guide, AC tonnage calculator, BTU calculator, best mini-split air conditioners and central air conditioner not cooling.
