What this tool does
Enter the existing and proposed SEER ratings, an annual cooling load (kWh) for the home, and an electricity rate. The calculator estimates kWh saved per year, dollar savings per year, and the rough payback period against the installed equipment cost.
How the math works
SEER is a cooling efficiency ratio: higher SEER produces the same cooling output with less input electricity. The savings formula is:
savings = annual_kWh * (1/old_SEER - 1/new_SEER) * rate
It is linear in the SEER differential — moving from SEER 10 to SEER 14 saves more than SEER 16 to SEER 20 in absolute kWh, even though the percentage improvement is similar.
Caveats
Real-world savings vary with climate, ductwork condition, refrigerant charge, runtime, and how the homeowner actually uses the system. Treat the payback number as a starting point for the conversation, not a guarantee.
