FreeHVACCalculators

SEER2 Energy Savings Calculator

Compare the yearly cooling cost of your current system with a higher-SEER2 replacement, and see how long the extra cost takes to pay back.

Method reviewed October 22, 2026. Version 1.0.0. How it works

Your inputs

Used only to convert an old SEER rating to SEER2.

Equivalent hours at full capacity. Roughly 600–1,000 in cooler northern climates and 1,500–3,000+ in hot southern climates; check a local source if you can.

Result

Estimated annual savings
$338
Cooling energy reduction
40.6%

Upgrading from 9.5 to 16 SEER2 would save about $338 a year at these assumptions.

Current system energy
4,547kWh
New system energy
2,700kWh
Current annual cooling cost
$833
New annual cooling cost
$494
Current efficiency as SEER2
9.5
Show the working
  1. Convert old SEER to SEER2
    10 × 0.95 = 9.5 SEER2
  2. Annual kWh = capacity × hours ÷ SEER2 ÷ 1,000
    old 36,000 × 1,200 / 9.5 / 1,000 = 4,547 kWh; new = 2,700 kWh
  3. Annual savings
    (4,547 − 2,700) × $0.183 = $338.3

SEER versus SEER2

Since 2023, U.S. air conditioners and heat pumps are rated in SEER2, measured under the DOE’s M1 test procedure with higher external static pressure that better reflects real ductwork. The same unit gets a lower number under SEER2.

To compare fairly, the calculator converts an old SEER rating to SEER2 using the AHRI factors adopted by RESNET: × 0.95 for ducted split and packaged systems, × 1.00 for ductless mini-splits.

How savings are estimated

Annual kWh = capacity × full-load cooling hours ÷ SEER2 ÷ 1,000, calculated for both systems at the same hours. The difference, multiplied by your electricity price, is the annual saving. Simple payback divides the extra purchase cost by that saving.

Full-load hours are the key assumption: the number of hours the system would need to run at full capacity to deliver a year’s cooling. They are a few hundred in cool climates and well over 2,000 in the hottest ones.

Worked example

These are the example values the calculator opens with, and the result the engine calculates for them.

Inputs

System size
3 tons
Current rating is
SEER (older label, before 2023)
Current efficiency rating
10
Equipment type
Ducted split or packaged system
New system SEER2
16
Full-load cooling hours per year
1,200 h
Electricity price
0.183 $/kWh
Extra cost of the higher-efficiency system (optional)
0 $

Result

Estimated annual savings
$338
Cooling energy reduction
40.6 %
Current system energy
4,547 kWh
New system energy
2,700 kWh
Current annual cooling cost
$833
New annual cooling cost
$494

Upgrading from 9.5 to 16 SEER2 would save about $338 a year at these assumptions.

Assumptions

  • Old SEER ratings are converted to SEER2 with a factor of 0.95 for ducted systems (the M1 test procedure uses higher external static pressure) and 1.00 for ductless systems.
  • Both systems deliver the same cooling over the same full-load-equivalent hours.

Limitations

  • Savings scale directly with full-load hours, which vary widely by climate and household. Treat the default as a placeholder, not a climate statistic.
  • Older equipment often performs below its original rating, so real savings from replacing it can be larger; installation quality can make them smaller.
  • Simple payback ignores financing, rebates, tax credits, maintenance and energy-price changes.

Frequently asked questions

How much does each SEER point save?

Savings shrink as efficiency rises: going from 10 to 14 SEER2 cuts cooling energy by about 29 %, but going from 16 to 20 cuts it by 20 %. Each point saves less than the one before, which is why payback for the very highest ratings can be long in mild climates.

What is the minimum SEER2 in my area?

Since January 2023, new split-system central air conditioners must be at least 13.4 SEER2 in the North and 14.3 SEER2 in the Southeast and Southwest regions (smaller than 45,000 BTU/h), with additional EER2 requirements in the Southwest. Split heat pumps must be at least 14.3 SEER2 nationwide.

Why might my real savings be larger?

Older systems often perform below their original rating after years of service. Replacing a system with a dirty coil, low charge or leaky ducts — and fixing those problems — can save more than the rating difference suggests.

Sources

  1. MINHERS Addendum 71i — SEER2 and HSPF2 Conversions — RESNET (factors developed by AHRI). SEER2/SEER = 0.95 and HSPF2/HSPF = 0.85 for ducted split systems; 1.00 / 0.90 for ductless.
  2. 2023 Central Air Conditioner Standards — FAQ — U.S. DOE, Office of Energy Efficiency & Renewable Energy. Regional SEER2 / EER2 / HSPF2 minimum efficiencies effective 2023.
  3. Electric Power Monthly, Table 5.6.A — average price to ultimate customers — U.S. Energy Information Administration. U.S. residential electricity price, 18.31 ¢/kWh in July 2026.

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