Corded vs cordless vs petrol lawn mowers – which costs more to run?

For the uninitiated, the lawn mower market can seem daunting – and expensive.

There’s a plethora of options out there, and they all tend to look relatively similar – four wheels, a handle and a spinning blade (there are, of course, some exceptions, such as wheelless hover mowers or fully automated robot lawn mowers). 

But the disparity in price is much greater than the disparity in appearance. We’ve tested mowers from £55 up to a whopping £1,240. We’ve found that price isn't necessarily an indication of quality, unearthing Best Buys as cheap as £150, and models for more than £500 that don’t even surpass a 50% overall score.

To be sure your next mower is top quality, see our lawn mower reviews.

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Lawn mower fuel types

Beyond their test performance, it’s not just the initial price you need to consider. Running costs are an important factor in any purchasing decision. 

A large proportion of running costs are what fuel the lawn mower uses. There are three options for powered lawn mowers: corded electric, cordless electric and petrol. And each type generally has its own set of advantages and disadvantages.

Pros and cons of corded lawn mowers

Corded mowers, also known as electric mowers, are powered by an electrical cord that needs to be plugged into an outlet. These mowers offer the advantage of being lightweight and easy to manoeuvre. They're generally quiet to operate and emit zero emissions, making them environmentally friendly. 

The biggest downside is their limited range due to the cord length. They need to be plugged in, which can restrict where you can mow and make them less suitable for larger lawns. You should also always use a residual current device (RCD) with a corded mower and ensure the cord is behind you as you mow to negate the risk of accidentally running it over. 

Corded mowers also tend to have less power than cordless or petrol models, so can struggle with longer grass or rougher grass types.

Try out Best Buy corded lawn mowers

Pros and cons of cordless mowers

Cordless lawn mowers, also known as battery-powered mowers, are a type of electric mower that runs on rechargeable batteries. This means they can be used anywhere without the range restrictions of a corded model, making them a versatile choice for larger lawns. They're also quiet and environmentally friendly, much like corded mowers. The improvement in battery technology means that many are now as powerful as petrol mowers.

On the downside, the mowing time is limited by battery life. Depending on the size of the lawn and the thickness of the grass, the battery may need to be recharged one or more times during use, which can be time-consuming. Additionally, they're usually heavier than corded mowers due to the battery, which can make them slightly less manoeuvrable.

Discover our Best Buy cordless lawn mowers

Pros and cons of petrol mowers

Petrol mowers are powered by internal combustion engines. They offer a high level of cutting power and are well suited for larger lawns or areas with thick grass. 

However, they do tend to be much heavier and noisier compared with electric mowers. They also require regular maintenance, including fueling and oil changes. 

Additionally, petrol mowers produce emissions and contribute to air pollution.

Check out our Best Buy petrol lawn mowers

Lawn mower running costs compared

To gather data on the initial costs and fuel costs of these three lawn mower types, we crunched the numbers from our past two years of testing. We’ve put 51 lawn mowers through our rigorous programme in that time – with more to come this summer – looking at five corded mowers, 30 cordless mowers and 16 petrol mowers.

• Electric corded mowers are by far the cheapest to buy up front, with an average initial cost of £127. 
• Petrol mowers are the second cheapest at £337, on average.
• Cordless mowers are the most expensive, with an average price of £423.

Prices are accurate as of May 2023, based on data sourced from online retailers and Which?’s pricing team.

Fuel costs slightly complicate the pricing situation. The price of the electricity or petrol used to mow an average UK lawn (188 square metres, as defined by a 2020 report from the Office for National Statistics) sees the order of expense change-up. While they have the highest initial cost, cordless models are by far the cheapest to use. 

• To mow an average lawn, our 2022 and 2023 tested cordless mowers cost just 6p. 
• This was followed by corded models, which cost 19p per time. 
• Petrol models had a much higher cost of 39p per average lawn mowed. 

To make our cost calculations, we used the current average price of a unit of energy under the government's Energy Price Guarantee – 33.2p per kWh, and the RAC’s average petrol price of 144.95 pence per litre, as of the 14 May 2023.

Petrol mowers are facing calls for regulation. Read more in our article on if petrol-powered gardening tools are going to be banned.

Hidden lawn mower costs

Let’s be clear – although these running costs are very far apart, there’s a long way to go for them to outweigh the differences in initial cost. 

In fact, taking those average prices, you’d need to mow that average lawn more than 2,300 times with a cordless mower before breaking even with an electric mower’s costs. To break even with a petrol model it's a significantly lower but still huge number of 270 times. 

But there are other costs to consider. Corded lawn mowers usually have the lowest maintenance costs among the three types. They have fewer moving parts than petrol mowers and no battery to replace like cordless models. Regular cleaning and occasional blade sharpening or replacement are the primary maintenance tasks. A new blade may cost £15 to £20, while professional sharpening services might charge £7 to £15.

Cordless lawn mowers can incur somewhat higher maintenance costs due to the battery. Most batteries will last for several years, but when a replacement is needed, it can cost anywhere from £35 to £150 or more, depending on the model. Otherwise, the maintenance tasks and costs are similar to those of corded mowers, involving mainly cleaning and blade care.

Petrol mowers have the highest maintenance costs. In addition to cleaning and blade maintenance, they require regular oil changes, air-filter changes and spark-plug replacements. An oil change might cost around £15 if you do it yourself, or more if you take it for a service. Air filters and spark plugs are relatively inexpensive at £3 to £10 each, but they do need to be replaced regularly. Moreover, if the mower requires any engine repairs, these can be quite costly.

But by far the most expensive part of maintenance is buying a new mower if the old one breaks down. Our 2022 survey of more than 5,300 lawn mower owners found that 12% of corded mowers ran into a fault in the first seven years of ownership, 16% of petrol mowers did and 8% of cordless mowers did. While these faults wouldn’t all lead to you needing an entirely new replacement, the percentages are indicative of which types tend to be more reliable than others.

Read more about our survey results and find out which brands are most durable in our guide to which lawn mower brand to buy in 2023.

The strongest performers in our tests 

While it’s clear that corded models are the cheapest way to go, it’s worth noting that, on average, they give the worst performance. Of all the corded models published on our site, they have an average overall score of 62%. They have a lower top-scorer, too, with the scores ranging from 50% to 74%. We’ve reviewed six Best Buy corded mowers.

Petrol mowers averaged an impressive score of 70%, with a range of scores from 59% to 81% and 13 Best Buys available. Although there are plenty of top-performing petrol mowers on the market, their environmental implications and high maintenance costs are major drawbacks. 

Cordless mowers average a score of 66%, ranging from 47% to 81%. They also make up the largest proportion of our Best Buys, counting 15. If you can manage the higher initial costs, these are the best available in terms of performance and sustainability.

Read our guide on how to buy the best lawn mower to find the right model for you.