Air Conditioning
Air Conditioning Running Cost Calculator
Daily and annual AC running cost
Updated July 12, 2026 · Live
What this tool does
Works out the daily and annual running cost of an air-conditioning unit from its cooling kW, efficiency, hours of use and your electricity price.
Enter the unit’s cooling kW, its COP, hours per day, cooling days and your electricity price; the calculator returns the daily and annual cost.
People also use
Formula Used
Works out the daily and annual running cost of an air-conditioning unit from its cooling kW, efficiency, hours of use and your electricity price. It runs entirely in your browser and shows the working, so you can check every step against your own figures.
How the air conditioning running cost calculator works
A unit’s electrical draw is its cooling output divided by its COP — a COP of 3.5 means 1 kW of electricity buys 3.5 kW of cooling. Multiplying that draw by the running hours and your electricity price gives the daily cost, and multiplying by the cooling days gives the annual figure. A higher COP cuts the running cost in direct proportion.
What you enter
Enter the unit’s cooling kW, its COP, hours per day, cooling days and your electricity price; the calculator returns the daily and annual cost. Every field is editable, and the result recalculates the moment you change a value.
Reading the result
The annual figure is what the unit adds to your bill; the COP is the biggest lever on it. Because you enter your own tariff and hours, the estimate tracks your real usage rather than a nominal rating.
Safe by design
This tool sizes the cooling load and running cost only. Refrigerant handling and the electrical connection are regulated work for a qualified F-Gas and electrical engineer.
Assumptions and limits
This assumes a steady average draw. Real consumption varies with outdoor temperature, thermostat setting and how hard the unit modulates. Electricity prices and cooling days are your own inputs, so nothing here goes stale.
Using it with the rest of BuildMetricLab
This calculator is one step in planning the job. Pair it with the related tools in this category and across BuildMetricLab to go from a single figure to a full costed plan — a sizing figure feeds a cost estimate, a cost estimate feeds a project budget, and each result carries straight into the next tool. Every BuildMetricLab tool runs entirely in your browser — no sign-up, nothing sent to a server, and the formula is shown on the page so the maths can be audited.
Sources & methodology
Works out the daily and annual running cost of an air-conditioning unit from its cooling kW, efficiency, hours of use and your electricity price. Every result is calculated from the values you enter, all inputs are editable, and no time-sensitive prices or rates are embedded.
Frequently asked questions
What is COP?
Coefficient of performance is the cooling delivered per unit of electricity. A COP of 3.5 means the unit produces 3.5 kW of cooling for every 1 kW it draws.
How do I cut running cost?
A higher-COP unit, fewer running hours, a higher set temperature and a cheaper tariff all reduce the cost — COP has the biggest steady effect.
Does outdoor temperature matter?
Yes. The hotter it is outside, the harder the unit works and the lower its real COP, so hot spells cost more than the average suggests.
Why enter my own price?
Electricity prices vary by tariff and region and change often, so entering your own keeps the running-cost figure honest.
Spotted something off?
Calculations or display — let us know.