Calculators / Heating and cooling

How much will a higher SEER2 save?

Put in your old system, your state and the new rating. You get the kWh and dollars a year, the payback, and DOE's minimum where you live.

Updated November 2026 · How we check our numbers

These are example numbers. Put in yours.

Your system

Equipment

Central ACHeat pumpHeats and cools

State

Size

tons

On the outdoor unit's model number: 24 = 2 tons, 36 = 3, 48 = 4, 60 = 5.

Old unit's rating

SEER (before 2023)SEER2

Old efficiency

SEER

On the yellow EnergyGuide label or the AHRI certificate. Units from the 1990s are often 10.

The new one

New efficiency

SEER2

Electricity price (optional)

¢/kWh

Leave blank for your state's average.

Extra cost of the efficient one (optional)

Yearly savings

$841 a year

A 3-ton air conditioner in Texas uses about 12,918 kWh a year at 9.5 SEER2 and 7,670 at 16. At 16¢ a kWh that's $841 a year, paying back $1500 extra in 1.8 years.

Old: 12,918 kWh9.5 SEER2
New: 7,670 kWh16 SEER2
Saved: $841a year
Payback: 1.8 years

Estimate for planning only, not professional advice. Check the manufacturer’s instructions, your local code and a licensed professional before you buy, build or install. Use at your own risk. Terms.

What it costs installed3 tons, NREL cost data

old = 10 SEER × 0.95 = 9.5 SEER2

cooling = 36,000 Btu/h × 3,409 h ÷ SEER2 ÷ 1000

saved = 5,248 kWh × 16¢ = $841

Other efficiencies

3 tons, Southeast

14.3 SEER28,582 kWh a year
$1,376/yr
The Southeast minimum for new equipment.
15 SEER28,182 kWh a year
$1,312/yr
Saves $759 a year against your old one.
16 SEER27,670 kWh a year
$1,230/yr
Saves $841 a year against your old one.
17 SEER27,219 kWh a year
$1,157/yr
Saves $914 a year against your old one.
18 SEER26,818 kWh a year
$1,093/yr
Saves $978 a year against your old one.
20 SEER26,136 kWh a year
$984/yr
Saves $1,087 a year against your old one.

Hours we used

DOE's averages for the Southeast: 3,409 cooling hours a year at full output. Your own bills are a better guide if your summers are milder or harsher than average.

Old ratings

Ratings before 2023 used a different test. We converted with AHRI's factors for ducted split systems: SEER × 0.95.

How we work it out

kWh a year = Btu/h × hours ÷ SEER2 ÷ 1,000 (plus Btu/h × heating hours ÷ HSPF2 ÷ 1,000 for a heat pump)

Hours are DOE's averages from its 2016 technical study, as the Federal Energy Management Program uses them: a central AC runs 3,409 full-load hours a year in the Southeast, 1,599 in the Southwest and 1,705 in the North. Heat pumps: 3,259 + 854 heating, 3,285 + 642, and 2,222 + 1,241. FEMP's own tables come out exactly with this formula.

Ratings before 2023 used a different test. DOE says SEER and SEER2 aren't directly comparable; AHRI's factors, adopted by RESNET, are SEER2 = 0.95 × SEER and HSPF2 = 0.85 × HSPF for ducted split systems. Since 2023, new split ACs must be 13.4 SEER2 in the North and 14.3 (13.8 at 45,000 Btu/h and up) in the Southeast and Southwest; split heat pumps 14.3 SEER2 and 7.5 HSPF2.

Where the numbers come from

Heating and cooling

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