What Size Post Hole Digger Do I Need?

Upgraded Home Team
by Upgraded Home Team
If you are installing a fence or other structure, you’re going to need a post hole digger. A post hole digger provides your fence structural integrity. It does this by

If you are installing a fence or other structure, you’re going to need a post hole digger. A post hole digger provides your fence structural integrity.

It does this by digging holes that are deep enough and wide enough for your needs. Picking the incorrect post hole digger will leave you unable to finish your fence. Alternatively, it could leave you doing a lot more manual work.

A post hole digger is designed to help you eliminate more work and make fence installation easier. So, it’s important that before you spend the money to purchase or rent a post hole digger, you know how to pick the correct size.

The size of the post hole digger that you purchase will largely depend on your fence post size. Generally, it is recommended that you provide yourself with 4 inches of wiggle room. So, if your fence post is 4 inches wide, you should consider an 8-inch post hole digger. This will provide you with enough room to properly set your posts. This is essential for erecting a post that is secure and sturdy.

Though choosing your post hole digger size is very important, there is much else to know about post hole diggers. If you’re going to be digging holes for posts, you’ll need to know it. This guide will walk you through some of the most important information. With it, you’ll have everything you need to succeed.

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Factors in Choosing Post Hole Digger Size

Picking a post hole digger that is 4 inches wider than the post is generally what is recommended. However, that may need to be adjusted depending on certain factors. There are several factors that influence the proper size for a post hole digger. Here are some of the additional factors that you should consider.

Fence Post Size

The most important factor is the post size that you are using. This can vary from 2 inches to 12 inches. Most often, poles are installed that range from 4 inches to 6 inches. For these post hole sizes, you will want to allow 4 inches of room. That means that for a 6-inch post, you will want a 10-inch post hole. One or two inches additional each way generally won’t hurt the integrity of the post.

However, for much larger post sizes you may need to allow additional room. That is because 4 inches of wiggle room looks much smaller when compared to a 12-inch post. For these large posts, you may want to select a larger post hole digger that provides more room.

Other factors do matter, but the most important one is by far the size of the posts that you are dealing with.

Fence Post Material

Another determining factor is the material that your posts are going to be made from. Heavier materials will often have different requirements. For instance, a post made of metal that is very heavy may want less room.

With less room, you can be sure that the hole can hold the post straight. Over time, any post will settle into the filled-in dirt or concrete. However, you can help the early stages by digging a hole that supports the post.

Setting Material

The final factor that will influence the post hole digger size that you choose is the filling material. This is the material that you use to surround the post once it is placed in the hole. This could be concrete, dirt, gravel, or another material.

You will want to take this into consideration when determining the width of the hole to dig. Some materials need more space to properly set. Other materials will need less room since they aren’t as strong.

Styles of Post Hole Diggers

Perhaps just as important as picking a post hole digger size is picking a style of post digger. There are three basic different types of post hole diggers. Each one is suitable for digging post holes, but you may have a preference based on their strengths. Here is an overview of each type

Manual Post Hole Diggers

If you are going to be doing light, shallow digging for your post holes, then a manual digger may be a good option. These devices do require a bit of work since they are not powered by anything but the person using them. However, they are generally more affordable.

It’s not recommended that you use a manual digger if you have heavy digging to do. This can quickly tire you out and render the device useless. Manual post hole diggers are also suitable for planting small trees or bushes. You can use them to build a small fence, but for anything large, it’s recommended that you upgrade.

Gas Post Hole Diggers

For larger holes and heavier projects, you may want to make the jump to a gas post hole digger. Gas-powered hole diggers are great devices that can cut through very tough soil and even clay. If you are dealing with tough terrain, a gas-powered hole digger might be the right option for you.

Another benefit to gas post hole diggers is that they are pretty mobile. This means you can take them to any job site since the power they use is connected to them. This is great for especially large properties. With a gas post hole digger, you won’t need to be near an electric source.

The downside to a gas-powered digger is that they can put off fumes that smell. If you’re sensitive and don’t need the mobility, you might consider an electric digger instead.

Electric Post Hole Diggers

The final type of post hole digger is electric. These diggers are connected to power through an electrical outlet. Electric post hole diggers are suitable for those that need high power but don’t need much mobility.

A downside to electric diggers is that they have to be near a power source to operate. This can be inconvenient. However, for most residential needs, they are suitable. They provide all the power of a gas-powered hole digger with none of the bad smell.

Another benefit is that they are generally more affordable than their gas counterparts.

Pre-Hole Digging Preparation

Before you dig your post hole with your manual, gas, or electric post hole digger, there are some things you need to know. This preparation will help you to have success during your drilling project.

Before you dig into heavy clay or soil that contains a lot of rocks and other debris, it’s a good idea to soak the ground. This will help to soften up the ground and ensure your time digging will be easier and faster. Wait a few hours to drill after you soak the ground to avoid a big mess.

Another critical step is to ensure you have all the necessary protection. You will want foot and leg pads to protect yourself from the drill. It’s recommended that you wear durable shoes and jeans. Top it off with good eye protection and you’re ready to go!

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Related Questions

How big of a hole do I need for a 4×4 post?

For a 4×4 post, it is recommended that you drill an 8-inch hole. This will give you 2 inches of room on each side. With this wiggle room, you’ll be able to comfortably install the post. You’ll also have plenty of room to put in the setting material of your choice. 

Can you put dry concrete in a post hole?

Yes, this is a common method. For some types, you can pour the dry concrete in the post hole and just add water! This is an easy and effective way to set a post.

Upgraded Home Team
Upgraded Home Team

We are a team of passionate homeowners, home improvement pros, and DIY enthusiasts who enjoy sharing home improvement, housekeeping, decorating, and more with other homeowners! Whether you're looking for a step-by-step guide on fixing an appliance or the cost of installing a fence, we've here to help.

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