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Air Conditioner Running Cost Calculator

Enter your unit's cooling capacity, efficiency rating, daily hours of use and how many months you run it each year. See exactly what your AC costs per hour, day, month, season and year.

Quick Start

Step 1. Find your AC capacity
Check the label or manual for cooling capacity in kW or BTU/h — use the toggle to switch units
Step 2. Enter efficiency rating
EER or COP from your unit's spec sheet. Use 3.0 as a safe default if unsure
Step 3. Set usage and season
How many hours per day and how many months per year do you run the AC?
Step 4. See running costs
Hourly, daily, monthly, seasonal and annual electricity costs appear instantly

Tip: Modern inverter ACs modulate compressor speed rather than cycling on and off at full power. Real consumption at moderate load is often lower than rated capacity ÷ EER suggests — use a plug-in energy meter for the most accurate daily kWh figure.

Just need a quick number? The simple version takes 10 seconds: Quick Estimate →

Project

AC Settings

Check label or manual. Typical split system: 2.5–7 kW (8,500–24,000 BTU/h).
EER or COP from spec sheet. Use 3.0 if unsure. Higher = more efficient.
Average hours you run the AC each day during the season.
How many months per year do you run the AC? Enter 12 for year-round.
Check your electricity bill for your rate.

Typical efficiency ratings by AC type

Indicative ranges only. Actual efficiency varies by brand, model, age and operating conditions. Check your unit's spec sheet for an accurate EER or COP figure.

Older fixed-speed split
EER around 2.5–3.0
Standard non-inverter units installed before 2015
Modern inverter split
EER around 3.5–5.0
Current mid-range and premium split systems
Portable AC unit
EER around 2.0–2.5
Less efficient; exhaust duct design limits performance
Window / through-wall unit
EER around 2.5–3.5
Self-contained units; efficiency varies widely by model

Common questions

How much does it cost to run an air conditioner per hour? +

A 3.5 kW AC with an efficiency rating of 3.0 draws around 1.17 kW of electrical power. At $0.28/kWh, that works out to roughly $0.33 per hour. The exact figure depends on your unit's capacity, efficiency and local electricity rate — use the calculator above for your numbers.

What is a good EER or COP for an air conditioner? +

For a standard split system, an EER of 3.0 or higher is considered good. Modern inverter ACs often reach 3.5 to 5.0. A unit with EER 4.0 uses 25% less electricity than an equivalent unit rated at EER 3.0 for the same cooling output.

Does setting a higher temperature save money? +

Yes. Raising the set temperature by one degree typically reduces electricity consumption by around 3 to 5%. Setting 24–26°C (75–79°F) instead of 20–22°C (68–72°F) across a full season adds up to a meaningful saving without affecting comfort for most people.

How does a split system compare to a portable AC? +

Split systems are generally more efficient. Portable ACs typically have EER ratings of 2.0 to 2.5, while a comparable split system often reaches 3.5 or higher. That difference can make a split system 30 to 50% cheaper to run for the same cooling output.

How much does it cost to run AC all day? +

Running a 3.5 kW AC (EER 3.0) for 24 hours at $0.28/kWh costs around $7.90 per day. At 8 hours per day the cost drops to around $2.63. Use the calculator above for an exact figure based on your unit and rate.

Understanding air conditioner running costs

How much does an air conditioner cost to run?

Air conditioner running costs depend on three things: the unit's cooling capacity, its efficiency rating (EER or COP), and your local electricity price. Divide cooling capacity (kW) by the efficiency rating to get estimated electrical power draw, then multiply by your rate and hours of use.

Cooling capacity and efficiency

A 3.5 kW split system with an EER of 3.0 draws around 1.17 kW of electrical power while running. The same unit with an EER of 4.5 draws only 0.78 kW — 33% less electricity for the same cooling output. When comparing units, the EER rating is the fastest way to estimate long-term running cost differences.

Seasonal vs year-round use

Most people run an AC seasonally rather than year-round. In temperate climates this is typically 3 to 5 months. This calculator lets you set months in use separately so you can see both seasonal cost and a full annualised figure side by side.

Inverter vs fixed-speed units

Fixed-speed ACs run at full capacity until the target temperature is reached, then switch off. Inverter units modulate compressor speed continuously. Inverter ACs are typically 20 to 40% more efficient in real-world use, especially during long continuous operation in moderate conditions.

Pro tip: Use a plug-in energy meter to measure your AC's actual daily kWh. Inverter units often draw significantly less than rated capacity ÷ EER suggests, because they modulate power based on load rather than running at full rated output.

Want to see how your AC compares against total home energy use? Try the Electricity Cost Calculator or compare against an HVAC Running Cost.

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