HVAC SEER2 Energy Savings Calculator

At the kitchen table, "higher efficiency" only means something when it turns into dollars. Put in the system size, the old unit's rating, the new SEER2 rating, and the local cooling hours and power price, and show the homeowner what each system costs to run for cooling each year, what they'd save, and how long a higher-efficiency option takes to pay back.

Runs in your browser — nothing you type is sent anywhere

Example numbers — replace with yours. The starting values are placeholders so the form isn't empty. They are not typical cooling hours, electricity prices, or ratings for any area. Use the homeowner's utility bill and hours that fit your climate.

The system

System size (tons) — placeholder 1 ton = 12,000 BTU/h of cooling. Use the same size for old and new. The current unit is rated in… Check the data plate or the AHRI certificate. Most units installed before 2023 only have a SEER rating. Current unit rating — placeholder The rating of the system being replaced, as printed. New system SEER2 — placeholder The SEER2 of the matched system you are proposing.

Usage and power price

Full-load cooling hours per year — example, set for your climate Hours the system would run at full capacity to meet a year of cooling. This varies a lot by climate and house: replace it. Electricity price ($ per kWh) — example, use the bill Total bill ÷ kWh used gives an all-in price per kWh. Years to count — placeholder How long the homeowner expects to keep the new system. Price difference between two options ($, optional) Extra cost of the higher-efficiency option. Leave at 0 to skip payback.

Good / better / best SEER2 levels (optional)

Enter the SEER2 of up to three options you're quoting. Leave one at 0 to hide it.

Good — SEER2 (placeholder) Better — SEER2 (placeholder) Best — SEER2 (placeholder)

Results

Current system: cooling kWh and cost per year —

New system: cooling kWh and cost per year —

Estimated savings per year —

Estimated savings over the years you entered —

Simple payback on the price difference —

Good / better / best comparison

Same size, hours, and power price; only the SEER2 changes. Savings are against the current unit.

Option	Cooling kWh / year	Cost / year	Savings / year	Savings over the years

What this means

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The math

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How it's worked out

Cooling load per year (BTU) = tons × 12,000 BTU per hour × full-load cooling hours.

Cooling kWh per year = cooling load ÷ (rating × 1,000). A SEER or SEER2 rating is BTU of cooling per watt-hour, so dividing by the rating gives watt-hours, and dividing by 1,000 gives kWh.

Cost per year = kWh × your price per kWh. Savings per year = current cost − new cost. Savings over the years = savings per year × years, at today's power price (no rate increases, no discounting). Simple payback = price difference ÷ savings per year.

Worked example

With the example numbers above (all placeholders, not typical hours, prices, or ratings):

Cooling load: 3 tons × 12,000 × 1,500 hours = 54,000,000 BTU a year.
Current 10 SEER unit: 54,000,000 ÷ 10,000 = 5,400 kWh × $0.15 = $810 a year.
New 16 SEER2 unit: 54,000,000 ÷ 16,000 = 3,375 kWh × $0.15 = about $506 a year.
Savings: 2,025 kWh, about $304 a year, or about $4,556 over 15 years.
Payback: $2,500 ÷ $303.75 = about 8.2 years.
Table: 15 SEER2 saves about $270 a year, 17 SEER2 about $334, and 19 SEER2 about $384.

SEER vs SEER2: why we don't convert

SEER2 ratings come from a newer Department of Energy test procedure than the older SEER ratings, so the same equipment can carry different numbers under each. You'll see rules of thumb for converting one to the other online, but we couldn't confirm a single official conversion factor from DOE for every kind of system, so this calculator doesn't apply one. If the old unit is rated in SEER, the result mixes the two tests and the page flags it. For the most honest comparison, compare SEER2 with SEER2 (the AHRI certificate for the matched system lists the ratings).

What this leaves out

This is an estimate, not a promise. Real savings depend on the home's actual cooling load, how the thermostat is set, how many hours the system really runs, duct leakage and duct losses, refrigerant charge and airflow on install day, and how the old unit has aged. Say so when you show it.

Heating. This covers cooling only. Heat pump heating savings (HSPF2) are not included.
Sizing. Old and new use the same tonnage here. If the new system is sized from a load calculation and comes out smaller or larger, the numbers change.
Power price changes. The lifetime figure uses today's price per kWh.
Rebates and tax credits. Anything that lowers the price difference shortens the payback. Check current programs yourself; we don't quote them here.

We don't quote "typical" cooling hours or electricity prices, because they vary by area and change over time. Use the homeowner's own bill and hours that fit your climate.

Related tools

Quoting three options? Put them on one printable page with the HVAC good / better / best proposal builder, and show the monthly payment for each with the HVAC financing payment calculator. Setting the prices for each tier? The HVAC install job pricing calculator builds a replacement price from equipment, labor, and overhead.