AC Running Cost Calculator

Calculate AC Running Cost

AC Type

BTU Rating

SEER Rating

Daily Usage Hours

Electricity Rate (¢/kWh) U.S. average ~16¢/kWh. Check your bill for your exact rate.

Cooling Season Length (months)

Your AC Running Cost

Based on EIA electricity rate data. Actual costs vary by thermostat settings, home insulation, and local climate. Results are estimates for budgeting purposes.

How Much Does It Cost to Run AC?

Air conditioning is typically the largest single contributor to summer electric bills. A central AC system running 8 hours per day at average U.S. electricity rates (16¢/kWh) costs $3–6 per day for a typical 2–3 ton unit, adding up to $90–180 over a 3-month cooling season. In high-rate states like California or Hawaii, that same system can cost $200–400+ per cooling season.

Window units are significantly cheaper to operate than central AC — a 5,000 BTU window unit running 8 hours costs only $0.50–0.75 per day. But they only cool one room, making them economical only when you need to cool a single space rather than a whole home.

Understanding BTU and SEER

BTU (British Thermal Units) measures how much cooling your AC delivers per hour. A higher BTU rating means a larger, more powerful unit that cools a bigger space — but also draws more electricity. Common sizes:

5,000–12,000 BTU: window units for single rooms
18,000–24,000 BTU (1.5–2 ton): small homes or apartments
30,000–36,000 BTU (2.5–3 ton): average U.S. homes (1,500–2,000 sq ft)
42,000–60,000 BTU (3.5–5 ton): larger homes

SEER (Seasonal Energy Efficiency Ratio) measures how efficiently your AC converts electricity into cooling. Higher SEER = lower operating cost for the same amount of cooling. As of 2023, the federal minimum for new central AC units in most regions is 14 SEER (15 SEER in the Southeast and Southwest). Older units installed before 2006 often run at 8–10 SEER, meaning they use 40–75% more electricity than a modern 14–16 SEER unit for the same cooling output.

AC Cost by Type and Size

Approximate cost per hour at 16¢/kWh (U.S. average 2026):

Window unit, 5,000 BTU, 12 SEER: ~$0.07/hr → $0.53/day (8 hrs)
Window unit, 10,000 BTU, 12 SEER: ~$0.13/hr → $1.06/day
Central AC, 2 ton, 14 SEER: ~$0.27/hr → $2.19/day
Central AC, 3 ton, 14 SEER: ~$0.41/hr → $3.29/day
Central AC, 4 ton, 14 SEER: ~$0.55/hr → $4.38/day
Central AC, 3 ton, 20 SEER: ~$0.29/hr → $2.30/day (29% cheaper than 14 SEER)

How to Reduce AC Running Costs

The most impactful changes ranked by typical savings:

Raise the thermostat by 4°F: Each degree warmer saves ~3% on cooling costs. Going from 72°F to 76°F saves ~12% — roughly $15–25/month in summer.
Use a programmable or smart thermostat: Automatically raises temperature when you're away or sleeping. Smart thermostats save 10–15% on average, or $15–30/month for typical central AC users.
Keep the condenser clean: A dirty outdoor condenser unit reduces efficiency by 5–10%. Annual cleaning (spray with a hose) keeps it running at rated SEER.
Replace the air filter regularly: A clogged filter reduces airflow and forces the system to run longer. Replace every 1–3 months during cooling season.
Seal air leaks: Air leaking through windows, doors, and attic penetrations can increase cooling loads by 20–30%. Weatherstripping and caulking are low-cost, high-payback improvements.
Use ceiling fans: Fans allow you to raise the thermostat by 4°F with no reduction in comfort. A ceiling fan costs ~$0.01/hr to run vs. $0.41/hr for central AC — a massive difference in operating cost.
Upgrade to a higher SEER unit: If your AC is 10+ years old, upgrading from 10 SEER to 20 SEER cuts cooling electricity use in half. With the IRA's 30% energy efficiency tax credit (up to $600 for AC), payback periods have shortened significantly.

AC Cost vs. Other Summer Appliances

To put AC costs in context, a 3-ton central AC running 8 hours uses about 13.7 kWh/day — compared to 1.2 kWh for a refrigerator running all day, 3.75 kWh for one dryer load, or 0.5 kWh for an hour of dishwasher use. AC dominates summer electricity consumption in most households by a wide margin, which is why thermostat management and system efficiency have an outsized impact on the summer bill.

For a full comparison of heating vs. cooling costs by season and region, see our Heating vs. Cooling Cost Calculator. For more on reducing summer bills, see our guide: How Much Does It Cost to Run AC All Day?

Frequently Asked Questions

How much does it cost to run AC per hour?

A typical central AC (3-ton, 14 SEER) costs about $0.36–$0.54 per hour at the U.S. average electricity rate of 13–16¢/kWh. A small window unit (5,000 BTU) costs roughly $0.06–$0.09 per hour. Use the calculator above with your specific BTU and SEER for an exact figure.

How much does it cost to run AC all day?

Running a 3-ton central AC for 8 hours costs roughly $2.90–$4.30 per day at average U.S. rates. A full 24-hour day costs $8.60–$13.00. In California at 25¢/kWh, that same 8-hour day costs $6.60–$9.90.

How much does AC add to the electric bill per month?

Central AC typically adds $87–$216 per month to your electric bill in summer, depending on system size, SEER rating, climate, and usage hours. A window unit adds $17–$65/month depending on size.

What uses more electricity, AC or heat?

In most U.S. climates, heating costs more annually than cooling because the heating season is longer. But central AC draws more power per hour (2–5 kW) than a gas furnace's electrical components. Electric resistance heating can exceed AC costs in cold climates.