Weed Eater vs. Lawn Mower – Head to Head Comparison

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Nothing gives off a good impression like a well-maintained lawn. It’s not only aesthetically pleasing to the eye but also good for your plants. But this is where the question arises: which do you need to keep things tidy, a lawn mower or weed eater? Both are garden equipment but which one does a better job?

A lawn mower is used to mow grass in large areas. A weed eater is also used to cut grass, but it can only handle a small amount. You can also use both. Let the lawn mower do most of the grass cutting and use a weed eater to trim the areas the mower cannot get to.

By the way, weed eater, weed wacker and string trimmer all refer to the same tool. They are used interchangeably so no need to get confused.

Lawn Mower vs. Weed Eater Quick Overview

Lawn MowerWeed Eater
Best used forCutting large areas of grassTrimming small grassy areas
Cutting width18 inches and higherUp to 18 inches
Learning curveEasyIntermediate
Power sourceGas, electric, cordlessGas, electric, cordless

How a Lawn Mower Works

There are many types of lawn mowers, but the push behind or walk behind type is the most widely used. When you turn on the mower, it activates the blades. Majority of mowers are equipped with a rotary blade for trimming weeds, grass and plants.

You can adjust how fast the blade spins and cuts. By controlling the blade you can direct it to cut the grass to a specific height. Gas mowers work differently from corded and cordless mowers. A manual lawn mower also runs under a different mechanism.

Lawn mowers will only perform well if properly maintained. It isn’t going to work if the spark plug leaks oil for example.

How a Weed Eater Works

A weed eater uses a nylon, wire or string to cut weeds, plants and grass. Also known as string trimmers and weed wacker, the tool runs on gas, electricity or battery (cordless).

When a weed eater runs, the string spins faster and faster. Due to centrifugal force, the line stiffens as it spins, enabling it to cut grass. Its cutting capacity depends on the power source. In general, gas string trimmers are the most powerful, while corded and cordless models are just about even now

Cutting Capacity

Lawn mowers have greater cutting capacity than string trimmers. You can use it to maintain small to large lawns and cut all kinds of grass. String trimmers are more suitable for cutting grass in small areas.

Lawn mowers. Its cutting capacity is measured in height and width and determined by its power source.

Cutting width. The width indicates the stripe width the lawn mower can cut.

  • Small lawn mowers: 11-12 inches
  • Medium lawn mowers: 15-16 inches
  • Large lawn mowers: 17 inches and greater

Cutting height. This indicates how high or low the grass cut will be. Most lawn mowers including the Craftsman M105 have a range of 3.2 to 5 inches. You can adjust the cutting height to suit your requirements.

Weed eaters. Their cutting capacity is determined by the string line size. The most powerful models have a 16-18 inch cutting width.

The most common sizes are:

  • 0.065-0.085 in.: cutting light grass
  • 0.085-0.110: thick grass and weeds
  • 0.110 and higher: underbrush cut

Most string trimmers support all three line sizes, but check your operating manual to be sure. The lines vary in shape too. Round is the standard but square, multi sided and others are available.

Ease of Use

Lawn mowers are easier to use. You either just push or drive it to where you want to go. Either way the blades do the work. Whether it is gas, electric or battery, the working principles are always intuitive to use.

Weed eaters require more effort to operate. You need to carry the tool as you use it and this can tire you out if you have to trim for hours.

New weed eater owners may also have trouble getting the right amount of string for cutting. The line feed works automatically but sometimes you might need more than what the spool gives. This is why some people prefer to remove the string trimmer guard to get more string.

Lawn mowers are not perfect and can run into problems too. But in general, they are simpler to use compared to a weed eater.

Weight and Maneuverability

Lightweight weed eaters weigh 5-6 lbs. while large, gas-powered models reach 10 lbs. before putting in any fuel. Lawn mowers weigh 100 pounds on average. But they get much heavier.

A light push mower weighs around 55-60 lbs. On the other hand you have zero turn and rider mowers which tip the scales at 500 lbs. or more. The bottom line is that lawn mowers are much heavier. But how does this affect maneuverability?

While lawn mowers are heavier, some might find them more maneuverable. Push mowers are very easy to use and anyone who knows how to drive can operate a rider mower. So while lawn mowers are heavy, they can be moved around well.

Weed eaters are lighter so you can position it anywhere you want. Once you get the hang of how it works you will find it a breeze to use.

Power and Longevity

Weed eaters and lawn mowers use different power sources, namely gas, electricity and battery. Battery and cordless are the same.

Gas powered weed eaters are more powerful than corded and cordless models. The Husqvarna 128LD can cut more grass and weed than the average string trimmer and in less time. It is ideal if you have to cut a good amount of grass.

But corded and cordless weed eaters are getting better and better. If you only trim a small area, an electric or cordless model is a practical alternative.

This is also the case with lawn mowers. Gas-powered models pack more cutting power than electric and cordless ones. But if you don’t need that kind of power, an electric or cordless lawn mower will suffice.

When to Use a Lawn Mower

Use a lawn mower if you want to cut a lot of weeds. It is the best tool for maintaining your lawn and also the easiest to use. If you have to trim grass and weeds in sizable areas, a lawn mower is the way to go.

Which type to use depends on the lawn size. In general:

  • 1000 square feet or less: electric or cordless lawn mowers
  • 1000 to 2700 square feet: high end electric and gas lawn mowers
  • 2700 square feet and larger: gas lawn mowers

If you have a large property that needs regular lawn maintenance, you should invest in a rider or zero turn mower. It is much easier to just ride and mow than push across a large area. They cost more but will benefit you in the long term.

Aside from gas, electric and battery, robotic lawn mowers are becoming more popular. They don’t have the cutting capacity of gas mowers and are expensive. But if you don’t like mowing and want an automated approach, a robot lawn mower might be right for you.

When to Use a Weed Eater

Use a weed eater to cut grass your lawn mower cannot reach. There is no reason why you have to choose a string trimmer or lawn mower when you can use both. Start by cutting most of the grass with your lawn mower and let the trimmer finish it off.

If you have a large lawn with areas that your mower cannot reach, get a weed eater. Use them both to for your yard work and you will get better results.

If you have a small lawn and only cut grass on occasion, a gas powered string trimmer is enough. As long as you don’t let the weeds grow too quickly your trimmer can handle it.