Do electric lawn mowers save more money than petrol?

When choosing a lawn mower, it used to be a fairly simple decision: a lightweight electric mower for the average garden, or level up to petrol power for bigger, tougher jobs. But as electric models improve, becoming more powerful and more versatile, they are more able to compete directly with the petrol models. In today’s market, a good quality battery-powered mower is comparable to a petrol-powered machine in terms of cutting power and extras – which means it’s more important than ever to compare costs.

The price of both petrol and electric lawn mowers can vary widely depending on brand, model, features and the size of the mower. However, generally, petrol lawn mowers tend to be more expensive than electric mowers, especially when considering the high-end models.

We asked the lawn mower experts at Hayter and Stihl for their insight into the key cost differences between petrol and electric mowers, so you can work out which type will suit your lawn and your wallet.

Are electric lawn mowers expensive?

“There are plenty of factors to consider when evaluating cost between the two fuel types”, says Chris Cooper, senior product manager at Hayter. The most obvious being that initial purchase price, followed by the ongoing running costs.

As electric mowers get bigger and more powerful, you’ll find that the price goes up accordingly. However, while cordless electric mowers are typically more expensive than the corded ones, electric mowers are often still far cheaper to buy than petrol mowers.

Electric mowers are also cheaper to operate since they don’t require refueling. All you have to do is plug them in – either directly into the wall while you mow if it’s a corded mower, or in advance via a charger if it runs off a rechargeable lithium-ion battery. Neither will add much to your electricity bill. And juicing up the battery of an electric mower is still likely to be cheaper than filling the tank of a petrol engine.

“A key benefit of battery-powered lawn mowers is lower running costs when compared to a petrol model”, says Paul Hicks, product manager at Stihl. “Even while energy prices are increasing, the cost of running a battery-powered lawn mower means they are still a good value option.”

So how much will a battery-powered lawn mower actually cost you to run? Let’s do some maths. At the time of writing (Jan 2025) the UK energy price cap is at 24.86p per kWh. The Bosch EasyRotak 36-550 cordless mower’s 36V 4Ah (144W) battery takes roughly 2 hours to charge, meaning it will cost you about 7.15p per charge.

Of course, the size of your garden is a key variable: if the Rotak 36-550 can mow a lawn up to 550m² in size on a single charge, and the average lawn in the UK is 255m², so in this hypothetical scenario you’d be charging once every two mows and paying around 3.57p per use.

This is just an illustration: to take a deep dive into the costs for different types of electric mower with our guide to lawn mower running costs.

Are electric lawn mowers more expensive to use than petrol mowers?

Buying petrol to refill your mower may seem like a bigger cost than using electricity, but that doesn’t mean a petrol mower is necessarily expensive to run. “While the price of charging a battery is cheaper than buying petrol, this all depends on the cost of petrol in your circumstance”, explains Chris Cooper.

The size of your garden will dictate how often you have to refuel and, as long as you’re not regularly trimming a football pitch or the grounds of a palatial estate, you’ll probably get multiple mows out of a single tank. If you’re just giving the average domestic lawn an occasional trim, you’ll only need to buy an appropriately-sized can of petrol each spring (you should always drain the tank over winter, or if the mower’s not in use for any extended period of time, as petrol left in it will degrade, potentially damaging the engine).

Similarly, as Chris points out, the same factors will also determine how often you’ll need to recharge the battery for a cordless electric mower. “A full tank of petrol will last longer than a full battery, especially if the brand of battery mower you choose has a smaller-capacity battery. If you have a very large garden or mow professionally, savings will become more noticeable if you invest in a mower with a much larger battery capacity”, he advises.

Cooper also suggests that if you’re a professional groundskeeper, landscaper or gardener then you may be able to benefit from claiming petrol as a business expense.

Electric vs petrol: How do the running costs compare?

The other ongoing cost of any lawn mower is maintenance. Petrol mowers will require more looking after – including regular oil changes, new spark plugs and the cleaning or replacing of air filters – so, again, electric mowers have the advantage if you’re just looking at the bottom line.

“As well as helping you save on petrol costs, battery mowers also don’t require engine oil or fuel treatment to keep in top condition”, says Chris Cooper. “While you won’t be buying these items constantly, it is another saving consideration to be aware of.”

Paul Hicks points to the complexity of a petrol engine, compared to a battery-powered model: “A petrol engine can have plenty of complex moving parts, but a battery-powered tool is a lot simpler”, he says. “They typically consist of a motor, wiring harness and electronic control module, meaning less maintenance is required.” Regardless, he still recommends taking your lawn mower for a yearly service, which should involve checking for damage to the mowing deck and could include sharpening the blades.

Of course, even battery mowers can have unexpected costs: for instance, the cost of eventually replacing the battery. If you opt for a budget-friendly battery, you may find it doesn’t have the capacity to do your whole lawn. That means having to buy a spare, so that you can switch them out mid-mow, or be left with the annoyance of a job half-done while you wait for the battery to recharge.

“While charging remains cheap”, says Cooper, “for frequent use, such as multiple lawns in a day, you may want to consider buying multiple batteries to shorten any possible downtime. This all comes down to the size of the battery you buy and the speed of the charger.”

When it comes to buying a lawn mower, brand loyalty can pay off too. Consider adopting the same manufacturer as your other power tools, since well-known brands often use standardised batteries that can be switched between their products.

Electric vs petrol: Pros and cons

So, on paper, electric mowers are cheaper, but that doesn’t mean you’ll save money, or even that they’re right for your particular circumstances.

“Garden size, noise and battery capacity are common considerations when choosing between a battery or petrol mower”, says Chris Cooper. “Smaller gardens don’t take as long to cut, meaning you can easily get multiple mows on one charge of your mower’s battery.”

Electric mowers do tend to be lighter, and they are easier to start, with just the push of a button, but they’re generally only suitable for small to medium-sized flat lawns. Corded models have practically unlimited runtime but are limited by the length of their cable, while cordless models offer more mobility but are limited by their battery life.

Cooper also points to the impact an electric mower has on the planet, not to mention your nose and ears: “Battery mowers have no exhaust, which means no engine emissions. Finally, battery mowers are much quieter than petrol mowers. Animals are extra appreciative of this, but it’s also handy if you share a fence with a neighbour who you don’t want to disturb.”

Meanwhile, petrol mowers will run as long as you have the fuel to put in them. They can be, and often are, heavier and harder to start (especially older models without electric start features) but that’s usually because they’re more powerful and that means they can take on tougher jobs, whether that’s larger lawns, longer grass or difficult terrain.

It’s also worth considering self-propelled lawn mowers, which do the hard work for you since they move under their own steam and all you have to do is steer – most electric models will require you to put more effort in. “Self-propelled mowers are a great option if you have a large garden and want to make mowing the lawn easier”, explains Paul Hicks. “A single-speed self-propelled lawn mower makes it easier overall to mow the lawn as you won’t need to push it, which is ideal if you have a large lawn or a garden on a slope.”

Electric vs petrol: Which is cheaper?

Ultimately, choosing between a petrol and electric lawn mower will depend on your specific needs and priorities. Electric mowers are usually cheaper – both in terms of the up-front price and the ongoing running costs – and for gardeners with a smaller lawn, or those who are looking for a more environmentally friendly, low-maintenance option, an electric mower is likely to be the better fit.

However, anyone with a really large lawn or some tough mowing conditions might consider spending more and levelling up to a petrol model with some more oomph. After all, when it comes to power, you get what you pay for.