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SEER Savings Calculator

Annual running cost difference between two SEER ratings.

Your measurementsEvery assumption editable01

Older systems are often 8–10. Check the nameplate.

Current minimums are around 14–15 depending on region.

Roughly 500 in a mild climate, 2,000+ in a hot one.

Annual savingCalculated live02

Result

$307per year

$691 → $384 a year

System output3 tons
36000 BTU/hr
Current consumptionat SEER 10
4320 kWh/yr
New consumptionat SEER 18
2400 kWh/yr
Current running cost
$691.2/yr
New running cost
$384/yr
Annual saving
$307.2

SEER is a seasonal average measured under test conditions, not a guarantee. Real savings depend on how the system is installed, whether the ductwork leaks, and whether the new unit is correctly sized — a high-SEER system that is oversized or connected to leaky ducts will not deliver its rating.

The saving assumes identical usage before and after. In practice people often run a cheaper system more, which is a real comfort gain but eats into the arithmetic.

Equipment cost, installation and available rebates are not included. Divide the installed cost by the annual saving for a crude payback period, and treat anything over the equipment's expected life as a comfort purchase rather than an investment.

Enter your system size, current and proposed SEER ratings, how many cooling hours your climate produces and what you pay for electricity. The result is the annual difference — which is the honest basis for judging an upgrade, rather than the percentage on the sticker.

Why use this tool?What it does differently03

Why use this tool?

Real currency, not percentages

A forty per cent efficiency gain on a small bill is a small number. Seeing it in dollars is what makes the decision.

Both costs shown

Current and proposed annual running costs side by side, plus consumption in kWh.

Climate aware

Cooling hours vary from about 500 in mild regions to over 2,000 in hot ones, which changes everything.

Honest about limits

SEER is a test-condition average. Ductwork, installation quality and sizing all affect what you actually get.

How this worksThe method04

How this seer savings calculator works

SEER is BTU of cooling per watt-hour of electricity, so annual consumption is system output times cooling hours divided by SEER times a thousand. Running that for both ratings and applying your electricity rate gives two annual costs.

The saving is the difference. Dividing an installed cost by that figure gives a crude payback period — and if the payback runs past the equipment's expected life, the upgrade is a comfort purchase rather than an investment.

SEER is measured under test conditions and is a seasonal average. Real savings depend on installation quality, duct leakage and correct sizing; a high-SEER system on leaky ducts will not deliver its rating.

How to use itStep by step05

How to use it

  1. Step 1: Enter the system size

    In tons. Use the AC size calculator if you are sizing a replacement.

  2. Step 2: Enter both SEER ratings

    Current from the nameplate, proposed from the quote. Older systems are often 8 to 10.

  3. Step 3: Estimate cooling hours

    About 500 in a mild climate, 1,200 moderate, 2,000 or more where summers are long.

  4. Step 4: Divide by installed cost

    For a rough payback period. Compare it against the equipment's expected life.

Example usageWorked figures06

Example usage

A typical upgrade
A 3 ton system going from SEER 10 to 18, running 1,200 hours a year at 16 cents: consumption falls from 4,320 to 2,400 kWh, saving about $307 a year.
A mild climate
The same upgrade with only 500 cooling hours saves about $128 a year — the identical equipment, less than half the return, because there are fewer hours to save across.
A high electricity rate
The same 1,200-hour case at 32 cents rather than 16 doubles the saving to about $614. Rate matters as much as the efficiency gain itself.
Frequently asked questionsCommon questions07

Frequently asked questions

How much will a higher SEER save me?

It depends on system size, cooling hours and your rate far more than on the SEER numbers alone. A 3 ton upgrade from SEER 10 to 18 saves around $300 a year at 1,200 hours and 16 cents per kWh.

Is a higher SEER always worth it?

In a hot climate with a long cooling season and high rates, usually. In a mild climate the payback can outlast the equipment, in which case you are buying comfort and quiet rather than savings.

What is SEER exactly?

Seasonal Energy Efficiency Ratio — cooling output in BTU divided by electrical input in watt-hours, averaged across a simulated season. Higher is more efficient.

Will I actually see these savings?

Only if the system is correctly sized and the ductwork is sound. A high-SEER unit on leaky ducts or oversized for the house will not deliver its rated efficiency.

Does this include installation cost?

No. Divide your quoted installed cost by the annual saving for a rough payback period, and factor in any rebates separately.

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