SEER Savings Calculator
See how much you could save on cooling by replacing an old air conditioner with a more efficient one. Enter your system size, the old and new SEER ratings, how much you run the AC and your electricity price, and this SEER savings calculator shows the yearly savings, the total over the life of the system and the payback time.
Your results will appear here.
How to use the SEER savings calculator
- Choose the size of the air conditioner in tons. One ton is 12,000 BTU per hour. The size is usually on the outdoor unit’s data plate.
- Enter the current SEER rating. Older systems from before 2006 are often 10 SEER or lower.
- Enter the SEER rating of the new system you are considering.
- Enter the full-load cooling hours per year. This is how many hours the AC would run if it always ran at full power. Hot climates have far more hours than cool ones.
- Enter your electricity price per kWh from your power bill, and the number of years you expect to keep the system.
- Add the extra cost of the more efficient system if you want the payback time.
SEER savings formula
Yearly kWh = Size (BTU/h) × Cooling hours ÷ SEER ÷ 1,000
Yearly savings = (Old kWh − New kWh) × Price per kWh
Payback (years) = Extra cost ÷ Yearly savings
SEER stands for Seasonal Energy Efficiency Ratio. It is the cooling output in BTU over a season divided by the electricity used in watt-hours, so a higher number means less electricity for the same cooling.
Worked example
You replace a 3-ton, 10 SEER air conditioner with a 15 SEER model. It runs about 1,000 full-load hours a year, and electricity costs $0.18 per kWh:
- Size: 3 × 12,000 = 36,000 BTU/h
- Old system: 36,000 × 1,000 ÷ 10 ÷ 1,000 = 3,600 kWh, costing $648 a year
- New system: 36,000 × 1,000 ÷ 15 ÷ 1,000 = 2,400 kWh, costing $432 a year
- Savings: 1,200 kWh × $0.18 = $216 per year, or $3,240 over 15 years
- If the 15 SEER system costs $1,500 more, the payback is 1,500 ÷ 216 = 6.9 years
How much electricity a higher SEER saves
| Upgrade | Cooling electricity saved |
|---|---|
| 10 to 14 SEER | about 29% |
| 10 to 16 SEER | about 38% |
| 13 to 16 SEER | about 19% |
| 14 to 18 SEER | about 22% |
| 16 to 20 SEER | 20% |
The percentage saved is 1 − Old SEER ÷ New SEER. Each step up saves a little less than the one before, so moving from a very old system to a standard one usually saves more than moving from a standard system to a premium one.
SEER vs. SEER2
Since 2023, new systems in the U.S. are rated in SEER2, which uses a test with higher airflow resistance that is closer to real ductwork. The same equipment gets a lower number in SEER2 than in SEER. Compare SEER with SEER, or SEER2 with SEER2, but do not mix the two in this calculator.
Tips for getting real savings
- Use your own numbers. Savings scale directly with cooling hours and electricity price. The U.S. Energy Information Administration expects the average residential price to be about 18 cents per kWh in 2026, but many states pay much more or less.
- Size the system correctly. An oversized AC cycles on and off too often and will not reach its rated efficiency. Ask for a load calculation before you buy.
- Fix the ducts too. Leaky or poorly insulated ducts can waste a large share of the cooling a new system makes.
- Look for rebates. Utilities and local programs often offer rebates for high-efficiency equipment, which shortens the payback time.
Frequently asked questions
How much will I save going from 10 SEER to 16 SEER?
About 38% of your cooling electricity. For a 3-ton system running 1,000 full-load hours a year at $0.18 per kWh, that is about $243 a year.
Is a higher SEER air conditioner worth it?
It depends on how much you use your AC and what you pay for electricity. In hot climates with high power prices, the extra cost is often paid back within the life of the system. In mild climates it may not be.
How many cooling hours should I use?
Use a number for your climate if your contractor or utility can provide one. Cooler northern areas may have well under 1,000 full-load hours a year, while hot southern areas can have 2,000 or more.
What does SEER mean?
SEER is the Seasonal Energy Efficiency Ratio: the total cooling a system provides over a typical season divided by the electricity it uses. A higher SEER means lower running costs.
Can I compare SEER and SEER2 ratings?
Not directly. SEER2 comes from a stricter test and reads lower for the same system. Compare ratings of the same type only.
Sources and methodology
The formulas on this page were written and checked by the HomeQuantly Team against the worked examples shown above. Results are estimates for planning; always confirm measurements on site before you buy materials.