SEER Rating Comparison Calculator
Compare two air conditioning units with different SEER ratings to estimate annual energy consumption and cost savings.
Typical home: 18,000–60,000 BTU/hr
Typical range: 500–3,000 hrs/year
Older/baseline unit (min federal: 13–14)
Newer/high-efficiency unit
US average ≈ $0.13/kWh (2024)
Typical AC lifespan: 15–20 years
Formulas Used
Annual Energy Consumption (kWh/year):
Energy = (Cooling Load [BTU/hr] × Annual Hours) ÷ (SEER × 1,000)
SEER (Seasonal Energy Efficiency Ratio) is defined as the total cooling output (BTU) divided by the total electrical energy input (Watt-hours) over a typical cooling season. Dividing by 1,000 converts Watt-hours to kilowatt-hours.
Annual Operating Cost:
Cost ($/year) = Annual Energy (kWh) × Electricity Rate ($/kWh)
Annual Savings (Unit B vs. Unit A):
Energy Savings = Energy_A − Energy_B
Cost Savings = Cost_A − Cost_B
Efficiency Gain (%):
Efficiency Gain = ((SEER_B − SEER_A) ÷ SEER_A) × 100
Assumptions & References
- SEER is measured under standardized ARI/AHRI 210/240 test conditions (outdoor temp 82°F, indoor 80°F dry-bulb / 67°F wet-bulb).
- Annual cooling hours represent the total hours the AC operates at full load equivalent — actual runtime varies by climate zone.
- Cooling load (BTU/hr) should reflect the unit's rated capacity, not peak demand; oversized units cycle inefficiently.
- The US Department of Energy minimum SEER standards (as of 2023): 14 SEER in northern states, 15 SEER in southern/southwestern states for new split-system central ACs.
- ENERGY STAR® certified units typically require SEER ≥ 15 (split systems) or ≥ 12 (single-package units).
- Average US residential electricity rate: ~$0.13/kWh (EIA, 2024); rates vary significantly by state ($0.09–$0.30+).
- This calculator does not account for installation costs, rebates, inflation, or degradation of efficiency over time.
- SEER2 (the updated 2023 standard using M1 external static pressure) ratings are approximately 4–5% lower than equivalent SEER ratings for the same equipment.
- References: AHRI Standard 210/240; US DOE Energy Efficiency Standards; EPA ENERGY STAR Program Requirements.