Is cooling capacity the same as electricity use?

No. Cooling capacity measures heat removed from the home. Electricity use depends on input power and efficiency. A 3.5 kW cooling unit at COP 3.5 uses about 1.0 kW while running.

How much does central AC cost per day?

A typical central AC running 6 hours can cost a few dollars per day, but the exact number depends on capacity, efficiency, climate, thermostat setting, and electricity rate.

Why does runtime matter more than the AC label size?

The compressor may cycle on and off. A larger or inefficient system running for many hours can dominate the bill, while an efficient unit with short runtime may have modest cost.

Can solar panels offset air conditioning cost?

Often yes, especially when AC load overlaps sunny afternoon production. Use the AC result as a summer load input before estimating solar ROI or system size.

What COP should I use for my air conditioner?

Use the rating label or equipment documentation if available. Otherwise, split systems are often around COP 3-4, ducted systems slightly lower after duct losses, and portable units lower.

Calculator

AC Running Cost Calculator

Estimate AC kWh plus daily, monthly, and seasonal cost

Air conditioning cost is not just the size on the label. The useful estimate converts cooling capacity into input power using efficiency, then multiplies by runtime and your local electricity rate. Use this calculator to compare central air, mini-splits, window units, and portable AC before sizing solar, adjusting thermostat schedules, or replacing inefficient equipment.

Enter Your Details

Start with the required inputs. Open advanced assumptions when you have a quote or utility details.

Fill in the form and click Calculate to see results.

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Air conditioning cost is a seasonal load decision; compare it with whole-home use before changing solar or tariffs.

How to Use This Calculator

Choose the air conditioner type, enter the cooling capacity in kW, then enter average daily runtime and your electricity rate in cents per kWh. Leave COP blank if you want the calculator to use a typical efficiency for the selected AC type. For the most realistic result, use compressor runtime during hot days rather than the number of hours the thermostat is switched on.

Formula & Methodology

Estimated input power = Cooling capacity (kW) / COP. Daily kWh = Estimated input power (kW) x daily runtime. Daily cost = daily kWh x electricity rate. Monthly cost multiplies by 30; season cost multiplies by entered cooling-season days. Defaults use typical COP ranges for split-system, ducted central, window, and portable air conditioners. Use nameplate input watts or measured smart-plug data when available.

Frequently Asked Questions

Estimate input power by dividing cooling capacity by COP, multiply by runtime to get kWh, then multiply by your electricity rate. If you know rated input watts, use that measured input instead.

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