Understanding the running cost of your appliances is one of the most effective ways to reduce your electricity bill. Whether you want to know how much it costs to boil a kettle, run your fridge, charge your laptop, or power your heating system, the process is straightforward.
In this step-by-step guide, you’ll learn exactly how to calculate the running cost of any appliance, using just three pieces of information: wattage, usage time, and your electricity price per kWh. We’ll walk through the formula, provide examples, and show you how to estimate daily, monthly, and annual costs.
If you want instant results without doing the maths yourself, you can use our free Electricity Running Cost Calculator, which works for every household appliance.
This guide will help you make smarter energy decisions, accurately compare appliances, and identify where your biggest savings can be made.
Why Knowing Appliance Running Costs Matters
Most households have no idea which appliances use the most electricity or how much they cost to run each day. Understanding these running costs is vital if you want to reduce your energy bill, choose more efficient appliances, and avoid unexpected charges on your monthly statement. When you know exactly how much an appliance costs to run, you can quickly identify areas where small changes lead to meaningful savings.
Learning how to calculate appliance energy usage also helps you compare old and new models, understand the impact of your electricity tariff, and make smarter decisions about when and how long to use specific devices. High-wattage appliances such as tumble dryers, kettles, ovens, and heaters can consume far more electricity than you might expect, and they often become “energy hogs” without you realising it.
By understanding the actual cost of running your appliances and how those costs change based on your tariff, wattage, and usage patterns, you gain complete control over your energy consumption. This knowledge is the foundation for reducing waste, improving efficiency, and lowering your electricity bills year-round.
What You Need Before You Start
Before you can calculate the running cost of any appliance, you only need three simple pieces of information. Once you have these, you can work out the daily, monthly, and yearly cost of any device in your home, or use our free tools to calculate it instantly.
1. Appliance wattage
Every appliance has a wattage rating that tells you how much power it uses. This is the most important number in any running-cost calculation. You can usually find the wattage in one of the following places:
- On the appliance’s rating label
- Inside the instruction manual
- On the manufacturer’s website
- By searching “[appliance name] wattage” online
If the wattage is shown as a range (for example, “800–2000W” for kettles), use the higher number for a more accurate cost estimate.
2. Your electricity unit price (price per kWh)
Your electricity bill charges you a price per kWh, which determines how much you pay for every unit of electricity you use. This number is essential for calculating the cost of running an appliance.
You can find your unit rate:
- On your most recent electricity bill
- In your energy supplier’s online account or app
- On your tariff agreement or welcome letter
Most homes currently pay between 28p and 34p per kWh, but your exact rate may vary depending on your tariff.
If you prefer, you can enter this number directly into our Electricity Running Cost Calculator for instant results.
3. Estimated daily usage time
The final piece of information you need is how long you use the appliance each day. This varies hugely from one appliance to another. Here are some typical examples:
- Kettle: Less than 1 minute per boil (approx. 0.02 hours)
- Fridge: Always on, cycling throughout the day (24 hours)
- Television: 3–4 hours per evening
- Laptop: Around 6–8 hours, depending on usage
- Washing machine: 1 cycle per day or every other day
If you’re unsure, estimate on the higher side; this gives you a clearer picture of maximum potential costs.
Once you have these three pieces of information, you’re ready to calculate running costs manually or enter them directly into our Electricity Running Cost Calculator or Appliance Energy Comparison Tool for faster, more accurate results.
Step-by-Step: How to Calculate the Running Cost of Any Appliance
Once you have your appliance wattage, electricity price, and estimated daily usage time, calculating running costs becomes very straightforward. Follow the steps below to work out exactly how much any appliance costs to run per hour, per day, or even per year.
Step 1 — Convert wattage to kWh
Electricity usage is always billed in kilowatt-hours (kWh), not watts.
To calculate how many kWh your appliance uses, apply this simple formula:
kWh = (Wattage ÷ 1000) × Hours Used
Step 2 — Multiply by your electricity price per kWh
Now multiply the kWh usage by your price per kWh (your unit rate).
This tells you how much that usage period costs.
Running Cost = kWh × Price per kWh
Step 3 — Calculate daily, monthly, and yearly running costs
Once you know the cost of one usage cycle, you can estimate larger time periods:
- Daily cost: cost × number of uses per day
- Monthly cost: daily cost × 30
- Yearly cost: daily cost × 365
This method works for every appliance, from fridges and freezers to TVs, laptops, gaming consoles, dishwashers, and heaters.
For a faster, more accurate breakdown, our free Electricity Running Cost Calculator handles all these calculations automatically and shows the total cost for any appliance.
Example Running Cost Calculations for Common Appliances
To help you understand how running-cost calculations work in real situations, here are some typical examples using common household appliances. These examples use an electricity price of 34p per kWh, which is close to the current UK average. Your exact costs will vary depending on your tariff, appliance wattage, and daily usage habits.
Below is a reference table showing estimated monthly running costs for popular appliances found in most homes:
Example Running Costs for Common Appliances
| Appliance | Wattage | Hours/Day | Monthly Cost (£) |
|---|---|---|---|
| Kettle | 2000W | 0.2 | £4.00 |
| TV | 100W | 4 | £4.08 |
| Fridge | 150W | 24 | £36.72 |
| Laptop | 60W | 8 | £4.90 |
| Washing Machine | 700W | 1 | £7.14 |
These examples highlight how dramatically running costs can differ based on wattage and daily usage. A fridge, which runs continuously, contributes significantly to your monthly electricity bill, while a laptop or TV uses far less energy despite daily use. High-wattage appliances, such as kettles and washing machines, can also become surprisingly expensive when used frequently.
If you want precise results tailored to your own appliances, you can enter wattage, usage time, and your electricity rate into our Electricity Running Cost Calculator and get instant daily, monthly, and yearly cost estimates.
Use the Appliance Running Cost Calculator for Fast Results
While it’s helpful to understand the formulas behind appliance running costs, calculating everything manually can become time-consuming, especially if you want to compare multiple appliances or estimate long-term energy usage.
To make things easier, you can use our free Electricity Running Cost Calculator to get instant, accurate results for any appliance in your home. Simply enter the wattage, daily usage time, and your electricity price per kWh, and the calculator will show you:
- Cost per hour
- Cost per day
- Cost per month
- Cost per year
You can also combine this with our Appliance Energy Comparison Calculator to see which appliances cost the most to run and where you can make the biggest savings.
Using these tools allows you to:
- Compare old vs new appliances
- Understand which devices are using the most electricity
- Plan your energy usage more efficiently
- Reduce your electricity bill without guesswork
If you want quick, reliable results without doing the maths yourself, these calculators give you clear insights into your appliance running costs in just seconds.
How to Reduce Appliance Running Costs
Once you understand how much your appliances cost to run, the next step is finding practical ways to reduce your electricity usage and lower your monthly bill. The good news is that small changes in behaviour and appliance management can lead to significant savings over time. Below are some of the most effective ways to cut appliance running costs without compromising on comfort or convenience.
1. Switch to energy-efficient appliances
Modern appliances with high energy ratings (A++, A+++, or their updated equivalents) often use 30–60% less electricity than older models. Upgrading appliances such as fridges, freezers, washing machines, or dishwashers can lead to long-term savings, especially if your current models are more than 10 years old.
When comparing new appliances, check the kWh per year figure on the label – this gives you a clear idea of annual running costs.
2. Use smart plugs and energy monitors
Smart plugs allow you to track exactly how much electricity each appliance uses in real time. This is one of the quickest ways to identify wasteful or inefficient devices. Many smart plugs also let you schedule usage, turn appliances off remotely, and monitor energy consumption trends.
This data pairs perfectly with our Electricity Running Cost Calculator for accurate cost estimation.
3. Turn off appliances entirely instead of using standby mode
Many household devices, TVs, game consoles, printers, chargers, and kitchen appliances continue to draw power even when not in use. This is known as standby power or phantom load.
Turning appliances off at the wall can save £50–£80 per year for the average household.
4. Unplug chargers and devices not in use
Phone chargers, laptop chargers, and smart speaker docks can continue to use electricity even when nothing is connected. Although individually small, these costs add up over time. Getting into the habit of unplugging unused chargers is a simple but effective money-saving step.
5. Compare energy tariffs and switch to a cheaper supplier
Your electricity price per kWh has the biggest impact on appliance running costs. Switching to a more competitive tariff, or opting for an off-peak or time-of-use plan, can significantly reduce the cost of running appliances such as washing machines, tumble dryers, or dishwashers.
Once you know your unit rate, use our calculators to see how different tariffs would affect your daily and monthly spending.
6. Adjust usage habits for high-wattage appliances
Some appliances are naturally more power-hungry. For example:
- Kettles use high wattage but run for a short time
- Electric heaters can be extremely costly to run
- Ovens and hobs are big energy consumers
- Tumble dryers use more energy than almost any other appliance
Using these appliances more efficiently, shorter cycles, full loads, lower temperatures, or alternative methods can lead to meaningful savings.
Frequently Asked Questions (FAQ)
How do I calculate an appliance’s running cost from its wattage?
To calculate the running cost of any appliance from its wattage, divide the wattage by 1,000 to convert it to kilowatts, multiply by the number of hours it runs, and then multiply by your electricity price per kWh.
Does a higher wattage mean an appliance is more expensive to run?
Generally, yes. Higher-wattage appliances use more power per hour, which increases running costs. However, usage time also plays an important role. A low-wattage device used all day (like a fridge) may cost more than a high-wattage device used briefly (like a kettle).
Which appliances use the most electricity in a typical home?
Some appliances consume significantly more energy than others. The biggest energy users are typically:
- Electric heaters
- Tumble dryers
- Ovens and hobs
- Kettles
- Fridges and freezers (because they run constantly)
- Washing machines and dishwashers
Running costs depend on wattage, usage time, and your electricity tariff.
How accurate are appliance running cost calculations?
The calculations are very accurate if you know the correct wattage and your electricity price per kWh. Actual costs may vary slightly due to efficiency, standby consumption, appliance age, and cycling behaviour. For the most accurate breakdowns, use our calculators to model real-world usage.
What if my appliance doesn’t show a wattage label?
If you cannot find the wattage on a label or manual, you can:
- Search the appliance model online
- Check your smart plug or energy monitor
- Estimate using typical wattages for similar devices
- Use the Appliance Energy Comparison Calculator to benchmark
Knowing the wattage is essential for accurately calculating running costs.
How can I check which appliances are costing me the most money?
Use a smart plug or home energy monitor to track live consumption for each device. Pair this with your electricity unit rate and a running cost calculator to identify the most significant contributors to your energy bill.