What Size Lawn Mower Do I Need? | Complete Guide!

What size lawn mower do I need? Whatever may be the size of your lawn (or acreage of your ranch), working out this math is important.

Measuring the size of the lawn and the speed at which you want to get the work done are essential factors to consider when calculating the size of the lawnmower. A small-sized lawn should be well taken care of with a 28-35 cm cutting width, medium-sized lawns may need around 35-40 cm cutting width. A large lawn is maintained well with a lawnmower of 105 cm cutting width.

Let us work on the calculation together. But before that, why be so selective about picking up the right-sized lawn mower?

Why is lawnmower size important?

Can’t you just buy any lawnmower for your lawn? Technically, yes, you can, but it is a very bad idea. There are several reasons it pays to research and spends some time buying the right sized lawn mower.

  • It reduces the time taken to mow your lawn.
  • The right size and power make it easy to mow uphill or on steep terrain.
  • It is easy to maneuver through challenging obstacles and patches.
  • The grass is evenly cut without leaving any patches behind.
  • It makes mowing easy.

These are enough points to push you to research and determine the correct sized lawnmower for your lawn care needs. So let us delve further into the details before finalizing a lawnmower purchase.

What should be the right size of my Lawn Mower?

What sized lawnmower do I need for my mowing success?

Different grades and sizes of mower contribute to the overall health of the lawn. The two most important things to keep in mind are the grade and the size of the mower. You need to figure out whether you are better off with an entry-level or a mid-grade mower. It is the right blend of the two that offers maximum efficiency.

Choosing by lawn size

  • 1-acre lawn size

Suppose you own a small-sized lawn of 1 to 1.5 acres or even less. In that case, a single-cylinder engine with less horsepower should be sufficient. These do not pull loads but are great to meander through obstacles. The type is durable and trouble-free to operate.

A riding or a push lawn mower should do the task. Look to buy a riding lawn mower with an engine of 14-16 HP and a deck width of roughly 42 to 46”.

  • 3-acre lawn size

For a 3-acre lawn size, a riding lawnmower with an 18-24 HP with a deck width of 46-54” should suffice.

  • 5 acre and larger lawn size

Purchase a mid-grade mower that is powerful and versatile. An 18-24 HP engine with at least a 48″ deck size should do the trick here. With their twin-cylinder engine, these boast low-end torque and higher horsepower.

Measuring the cutting deck

What does a cutting deck say of 50” mean? Does it mean that the blade can cut across 50”? Or is the top of the blade 50”?

The deck size signifies that the bigger it is, the more you can mow in a single pass without moving back and forth in the same place. So you now see why buying a mower with a large deck for a small lawn does not solve the purpose. It gets awkward to mow and does not give an efficient cut.

This is the reason why you need to understand the right lawnmower size match for your lawn size.

Here are the steps to measure the mowing deck:

  • Put the mower in neutral and prop it on an elevated surface.
  • Measure the blade diagonally to get the cutting edge.
  • If the blade measures 15″, then the mowing distance is 15″.

Choosing by the distance between obstacles

Glance around the laying of the land to spot the natural and man-made structures. Access the distance between the trees, gates, and other obstacles on the lawn. If the terrain is hilly, you may want a lawnmower with a smaller deck size to avoid digging up the yard. The deck size should be such that it fits through the space allotted when driving the mower.

Choose by how much time it saves

Mowing should not be a full day’s task. You desire a safe experience with a quality cut, but saving time is crucial, especially when this is a weekly chore.

A large deck size and more HP let you finish the job faster. The idea is to estimate the amount of turf that the mower can mow in one hour in acres, square meters, or square feet based on the mower’s speed and width.

It is a no-brainer that the larger the size of your lawn, the more are your mowing needs. Large mowers have a large cutting width. It is highly unlikely that a large mower with a powerful engine will have a low cutting width.

Choosing by Lawn Size

Keeping the other factors like the power, size collector, and the need for a self-propelled mower aside and considering the lawn size, here is the right mower size based on the cutting width.

Lawn size in meter squareRecommended Mower size (cutting width in cm)
0-100< 30
100-50040-44 Push mower
250-75040-44 Self Propelled mower
250-100045-49 Push mower
500-150045-49 Self Propelled mower
750-200050-54cm Self Propelled mower (Engine -175 cubic centimeters)
1000-300050-54cm Self Propelled mower (Engine + 175 cubic centimeters)
1000-300055-59cm Self Propelled mower

While it may be tempting to buy a large-sized lawnmower to finish the task faster, it is also important to consider the tight corners and the small spaces when taking this decision. Small mowers may be capable of negotiating more easily here.

Understanding HP in Lawn Mowers

HP or horsepower is the measure to rate power in the lawnmower. It lets you understand the maximum workload and the ability of the mower. Horsepower measures work and not the size of the mower. If the machine is big and heavy, it will have more HP, which lets it handle heavy loads and tasks.

Read more: How to Cut Tall Grass? Tips to Mow it Efficiently

Understanding CC in lawn mower

CC or cubic centimeters is larger when the engine is larger. Typically in 1 HP, it is 14-17 cc. CC is something that you will see everywhere when you buy a lawnmower.

If you’re a masochist and want to go 100% natural, here’s your guide on how to Cut Grass without a Lawnmower.

Zero-Turn vs Riding Mower

Both the above mower options need little physical exertion and are thus suitable for more extensive lawns. However, you may still find yourself torn between a zero-turn and a riding mower.

A zero-turn mower does not have power on the frontal wheels. These are great for an expansive level lawn but do not work well on hilly terrains. If there are many trees and obstacles on your lawn, then the zero-turn mower is what you need.

In terms of speed, zero-turn mowers cut at 5-8 mph, whereas a riding lawn mower cuts at 3-4 mph.

Lawn size in acresRecommended ride on Mower size (cutting width in inch)
< 1 acreLawn ride on 30-42 inch CW
Zero-turn ride-on: 42 inches CW
Up to 2 acresLawn ride-on: 46-48 inch CW
Zero-turn ride-on : 46-48 inch CW
More than 2 acresLawn ride-on : >50 inch CW
Zero-turn ride-on: 50-60 inch CW


Buying a lawn mower is not a straightforward decision. There are lots of things that need consideration. It presents to you a maze of choices that can lead to making stupid mistakes. While there are several factors that you need to research, the lawnmower size does impact the quality of cut and the ease of mowing your lawn.

This article is also available in Hungarian: Milyen fűnyírót vegyek? | Teljes útmutató!

About Jennifer Igra

Growing up in Brooklyn, New York City known for it’s green gardens. Jennifer, a 30 year old gardener and green living fanatic started Igra World to share her gardening journey and increase gardening awareness among masses. Follow Igra World to improve your gardening skills.

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