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Use the calculator for an instant estimate, or read on for a full breakdown of how this cost is calculated.
Quick Answer
$75–$200/month (cooling season)
Varies by equipment & usage
AC energy use is determined by the system's size (in tons) and its SEER (Seasonal Energy Efficiency Ratio) rating. One ton of cooling equals 12,000 BTU/hr. A 3-ton unit running at full capacity draws 12,000 × 3 ÷ SEER watts — so a 14 SEER system draws about 2,570 watts.
That 2.57 kW running 8 hours a day for 30 days at $0.16/kWh equals about $99/month. In practice, AC cycles on and off, so actual runtime is less than clock hours — a 50% duty cycle halves that estimate.
Higher SEER ratings directly lower electricity draw for the same cooling output. Upgrading from 14 SEER to 20 SEER reduces energy use by 30% for identical cooling.
Estimate Your Cost
System size
3
tons
SEER rating
16
Hours per day
8
hrs
Electricity rate
0.16
$/kWh
Est. monthly cost
$43.20
~3,240 kWh/year
System size in tons (1.5–5 tons for most homes)
SEER rating — higher is more efficient (modern minimums are 14–15 SEER)
Local climate and number of cooling degree days
Home insulation quality — better insulation means shorter run times
Thermostat set points — each degree warmer saves roughly 3% on cooling costs
Duct leakage — leaky ducts can waste 20–30% of conditioned air
Electricity rate in your area
Pro Tip
The biggest savings usually come from upgrading the least efficient items first. Use Watt Wisdom to see exactly which loads are driving your bill before spending money on improvements.
Watt Wisdom calculates your full household energy profile — every appliance, your climate zone, and your usage habits — and tells you exactly what's driving your bill.
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