How Often Should Lawn Mower Blades Be Sharpened or Replaced

A sharp lawn mower blade cuts grass very efficiently while saving both time and effort. The blade cuts grass cleanly and allows the grass to recover faster and stay greener.

However, if the blade is dull, it weakens the grass and leaves the risk to promote grass diseases.

The time length of your mowing operation and substances other than the grass on your yard influence how often you need to sharpen the blade.

Both professional and home mowers might find it difficult to get how often to sharpen lawn mower blades. It may seem that the blade is sharp to your eyes, but still, it requires sharpening depending on your usage. 

Here in this article, I will tell you about when it’s the right time to sharpen the blade and additional tips to keep the blade sharp for a long time.


Lawn Mowing Intensity

As I mentioned earlier, the intensity of professional lawn mowers and homeowners isn’t the same.

Most homeowners spend more or less 30 minutes on average to cut the grass of their yards; not everyone does it every day. 

Some individuals mow once every couple of weeks just to keep the neighbors’ claim so that they don’t tell or send letters in the mailbox to remind them about cutting the grass. Such homeowners don’t care about how their lawn looks at all.

Another scenario is that most people do it once every week or twice a week. Their lawn mower blades are used more than the blades of those who do it every other week. These people care about their lawns.

No wonder there are people who prefer to mow everyday or every other day. They primarily do it so that their lawns always look great and in the right shape and size. 

On the flip side, there are lawn mowing service providers who have to deal with multiple lawn yards each day. Their working intensity is the highest.

Another important fact that influences how long the blade lasts is what the blade has to deal with other than just grass. If there are sticks and stones in the turf that the blade has to undergo through, it’s inevitable that the blade requires more sharpening.

How Often Should You Sharpen Lawn Mower Blades?

Lawn Mower Blades Be Sharpened or Replaced

The general rule of thumb is to sharpen a lawn mower blade every 25 hours of run time; that means it’s pretty much once a week.

Now, you might say that it’s a bit excessive, especially if you are a homeowner and use to mow the yard once or twice a week. The thing is, you don’t need to sharpen the blade once a week.

As the professionals have to deal with almost 20 to 25 hours mowing work per week, so, basically this general rule of thumb directly applies to them. 

You can also follow this advice and get the blade sharpened whenever the machine hits 25 hours of cutting time.

Consider using a mobile app that can monitor the actual time that you spend while cutting grasses. 

There are people who prefer to sharpen the blade once or twice every season. Mostly, it’s at the beginning and middle of the season, depending on the location where they live. 

This 25 hours rule ensures that there is nothing wrong going with the yard as well as turf grasses. Worth noting that your blade might need sharpening after 20 hours, depending on the cutting intensity and the condition of the lawn yard.

How Many Hours do Mower Blades Last?

As I have mentioned earlier, a typical lawn mower blade will last about 20 to 25 hours until you require to sharpen it again

How Often Should You Replace Lawn Mower Blades?

If you are concerned with the overall lifetime and ask this question “how often should I change my lawn mower blades,” a typical lawn mower blade lasts around 100 to 200 hours depending on the material and mowing intensity. 

If the mowing area has lots of stones and sticks here and there that the blade has to deal with while cutting grass, it will warn down and get nicked faster. 

You will need to sharpen more, and it will reduce the overall lifespan of the product as well.

As far as the highest quality blades are concerned, they will provide you with an overall 400 hours of run time until you need to replace it.

[On a side note, if you aren’t sure which type of mower blade you are using, read this.]

How to Know When the Blade Requires Sharpening?

Not everyone needs to sharpen their blade after every 25 hours of run time as the dullness of the blade largely depends on other conditions, such as blade material and yard condition. 

If you sharpen the blade too often than what it needs, it will significantly reduce the overall lifespan.

Look for following symptoms to determine when the blade needs to be sharpened:

  • Unevenness in Lawn

The very first sign you will be able to check easily is the cutting quality of the lawn. Each grass should be cut while maintaining the same height. 

There will be no unevenness of the top of the grasses. If you notice that the lawn is uneven after a mowing session all the way around, this is because of the dull blade.

  • The Quality of Mowing

A dull blade cannot properly cut the grass; it will tear the lawn. You might see frayed brown edges on the tip of the lawn, which is a clear sign of a dull blade. 

If the tips are mostly torn and not properly sliced, then consider sharpening the blade soon. 

Tearing and torn grass tips highly affect grass health. If you don’t resolve the matter soon, the grass will turn brown within any time.

  • Check the Blade

You can also determine whether the blade needs to be sharpened or not by inspecting the blade itself. Take a close look at the cutting edge of the blade. 

If you see large dents or chips or cracks in the edge, the blade is dull. Such an inconsistent blade is most likely to tear the grass rather providing you a cleaner cut. 

Furthermore, check the thickness of the blade as well. 

Over time, sticks, stones, sand, dirt, and debris erode the blade and weaken the metal that it feels paper-thin when you look at it. 

If this is the case, consider replacing the blade soon; otherwise, the blade can break anytime while running the machine and can injure someone.

Lawn Mower Blade Maintenance: How to Make It Last Longer?


In most cases, people need to replace their lawn mower blade soon due to doing some abusive stuff. You can actually prolong the lifetime of the blade by following some simple tips.

  • Before you start mowing, make sure there is no stone, stick, or little toy in the yard so that the blade doesn’t get contacted with such objects accidentally.
    If you don’t care about cleaning the yard from such materials, your blade will always mess up while mowing and require you to sharpen it more than usual, and you will need to find a replacement sooner.
  • Be sure to sharpen the blade every 20 to 25 hours of usage. If you sharpen the blade in time, it will leave less damage to the edge. Don’t attempt to get a replacement before trying to sharpen first. In most cases, sharpening does the trick. 
  • Last but not least, you need to figure out how to sharpen the blade correctly. Although it is mentioned at last, it’s an essential thing to consider. If you don’t know how to do it properly, the blade may accidentally wear off some of its materials on the edge, which reduces the overall lifespan.

Additional Tip

You can consider having a secondary spare blade if you have to mow more frequently. Whenever you notice the current blade is dull, you can pick the second one and keep mowing without putting pressure on the dull one. 

Also, you can continuously rotate using both of these blades more efficiently while increasing the lifespan of both the blades.

Be sure to keep the spear blade sharp when you are working using the other one so that your lawn mowing task doesn’t resume

What’s the Cost of Sharpening a Lawn Mower Blade?

You can sharpen the blade all by yourself, or you have the option to let someone else do it for you. There are standard blade sharpeners that you can buy for $20 or less. 

If you decide to send the blade to a repair shop, they will charge around $10. Although it seems a cheap deal, however, the quality of the blade will be compromised, and you may end up buying a new blade from the same shop.

Keeping this thing in mind, getting a sharpener seems a cost-efficient deal as you have to invest in one and sharpen multiple numbers of blades pretty much countless times.

You can also get a replacement blade around $20 to $30, depending on the type or model of your machine

Don’t pursue a new blade at first, if it’s only about dullness, sharp the blade properly, and your lawn mower machine will perform like a professional one.

Final Words

Now that you know how often to sharpen lawn mower blades, you don’t have to struggle to mow the yard anymore. 

Be sure to check the factors that tell you when it’s time to sharpen the edge and do it as soon as possible. You can also consider getting a spear blade that will significantly increase the lifespan of the blades.

Was this article helpful?

Leave a Comment

Your email address will not be published. Required fields are marked *