How to Determine Drill Bit Size for Wall Anchor: Quick Solution

Wall anchors must be the mainstay of your DIY arsenal for several reasons and advantages. Drywalls require anchors before you tend to hang any heavy picture frames, clocks, or different-sized mirrors and framed canvas. Nails are harsh for drywalls as they create gauges and cracks on the wall and make the wall look ugly. The same goes with screws. Besides, drywalls are incapable of holding a nail in place tightly and snugly to support a heavy framed piece of art. That’s why it is important to know how to determine drill size for wall anchor.

How to Determine Drill Bit Size for Wall Anchor

For a proper process, a wall anchor with the right size of a drill bit is what you need. But most DIYers and beginners don’t know how to determine drill bit size for wall anchor. As it will carry some pounds to hang a piece of work, the proper size of a drill bit is an important part of the whole process.

There are several types of drill bits you will find in the market. But it’s necessary to remember that not all types of drill bits are applicable to your drywall. If you once learn the type of those drill bits, you will know what size you should apply to your drywall to hang aesthetic frames. Let’s talk in-depth.

Drill Bits that are Appropriate for Wall Anchor

It is a matter of great relief that you don’t have to suffer much to find out which size is fit for the wall anchor. You must select a drill bit that suits the size of the screw and also the wall anchor. Unnecessary deep holes will make your wall look ugly. However, the drywall anchor itself is capable of measuring the size it needs. Mostly, drywall anchors of plugs prefer the exact diameter drill bit to create a hole.

The exact measurement will come out when you measure the shank of a drill bit first and then cut the extra portion measuring it against the flange. Another way to find out the size is to check the packaging of the drywall anchors. You will find the anchor diameter mentioned there. Thus you can pick up the right drill regarding it.

However, from some expert opinions, drill bits that are ½ inch in size are perfect. But they are more perfect for Snap toggle anchors and Flip toggle anchors. A convenient procedure should be followed, however, and that is drill bits that allow your anchor to tuck in with just a little push should be picked up.

Types of Drywall Anchor

To know what size your wall anchor needs of drill bits, you should first learn the types of drywall anchors. That’s because it is the only way you can tell or comprehend what size of the drill bit will fit into your wall anchor. Otherwise, mistakes will happen and you’ll find trouble getting the right size. Therefore, let us learn about the different types of drywall anchors first.

a) Toggle Bolt

Toggle Bolt

If you are obsessed with the traditional method, toggle bolts should be your choice. These bolts require two parts. One is the toggle and the other is the machine bolt. To hang extremely heavy framed items, you should adopt toggle bolts without any doubt. As these bolts are made with strong material, heavy and delicate items are safe in their hands. Materials like TV brackets and heavy shelves that weigh more than 300 pounds also get fit in their hands.

However, you need to follow certain steps to install a toggle bolt. Creating a pilot hole for this bolt is convenient and it is required as well. But there are some problems you will find while using the metal-made toggle bolts. They seem to be less capable to keep up with the level of the wall. Moreover, you will find a feature of a fast zip bind.

This will allow you to install and replace the anchor with another one in the most convenient way possible. For choosing drill bits size, follow the chart on the packaging. It should carry the size chart for toggle bolts. However, for these bolts, the size 5/16” of drill bits seems almost fine.

b) Molly Bolt

Molly Bolt

Another convenient bolt is the molly bolt. Molly bolts come with much strength to hold heavy items just like the toggle bolt. These bolts are the safeguard for professionals and they recognize these as hollow drywall anchors. They ensure immense safety and protect your wall from major damage. The fun fact about molly bolts is they care little about the anchor. You can replace a bolt with another molly bolt and you don’t have to think about the anchor.

Most of the molly bolts are made either of zinc-plated steel or plastic. The benefit of these material-based molly bolts is they carry an expansion feature. Thus when you install these bolts, the sleeve of the metals stretches out to the wall anchor to get fit in. to protect these drywall anchors, you can adopt ½” drill bits.

c) Plastic Anchors

Plastic Anchors

These plastic anchors have a great resemblance to molly bolts. As plastic tends to stretch out, these plastic anchors also expand conveniently. But these anchors are cheap and not durable at all. If you are want to hang very lightweight items like a mirror, a simple artwork, or a medium-sized canvas then you can choose these as a go-to anchor.

Try not to hang materials that are over 20 pounds. Otherwise, choosing these anchors would not be a great idea. Still, you can rely on these plastic anchors because they provide immense grip. When you try it with the screw, these plastic anchors will expand and snug inside perfectly. To determine the size of the drill bit, adopt the ½ inches ones for these anchors.

d) Self-Drilling Drywall Anchors

Self Drilling Drywall Anchors 2If you are searching for a less troubled process with anchors, then self-drilling drywall anchors are a fit choice for you. These anchors resemble screws. If you are lazy to drill your wall beforehand then these anchors will make your path easy.

You can easily apply the self-drilling drywall anchors without drilling any hole on the required area before. For hanging tough items with heavyweight, you can rely on these anchors with certainty. For the drywall, these anchors are the perfect match.

How to Determine Drill Bit Size for Wall Anchor Through A Chart:

Mounting something on the wall can be heavy or less heavy in weight. The weight of the item does matter as it determines the anchors and size of drill bits as well. Even if you just select the right screw, that’s not enough to accomplish the whole process. It’s more important to get acquainted with the size of drill bits after learning the different types of drywall anchors.

So far, you can already assume that as the drywall anchors are of different sizes and potentials, there you can find drill bits also of different sizes. You cannot fit an anchor with the wrong size of drill bits. This will increase the risk of mounting your delicate items on the wall.

It’s always wise to pick up a drill bit a little smaller than the plug of wall anchor. By following this strategy while drilling a wall made of concrete, you will get the anchor snug perfectly inside the predrilled hole. For beginners, you can simply create a pilot hole picking up a smaller drill bit at first. And then, you can proceed with your work.

However, we’ve prepared a chart regarding the size of the drill bit for your convenience. This chart includes wall plug color and screw size that determine the right drill bits size. If you just take an intense note of the whole chart, you will never feel the trouble of picking up the right size of drill bits for your wall anchor. So, let’s check it out.

Screw Size



6-10 4-8 10-14 14-18
Wall Plug Color



Red Yellow Brown Blue
Drill Bit Size



6 5 7 10

Things You Should Do If the Plug Size is Unknown

The list we have created can be used for almost all kinds of and different colors of wall plugs. But it can also happen that a different color appears in front of you and you don’t know how you are going to determine the size afterward. Therefore, learn a trick that we are going to provide you now before you get lost in trouble.

Step 1:

First, collect a piece of cardboard. Then choose a bit. Make sure you have that much knowledge to at least assume a bit that is almost capable for the plug size.

Step 2:

Then, drill the piece of cardboard with that bit. Here, you need to be a little careful as you should not cross the limit of making the hole on the board more than the diameter of the drill bit. To maintain this measurement, handle the driller in a way that it should not move sideways and stick to the particular direction.

Step 3:

After that, place the plug into the hole of the board. Its teeth should catch the sides of the hole of the board. If you see the teeth fail to reach the side of the hole then a smaller drill bit should be used. And if you see the opposite is happening, then choose a bigger one and apply the same trick until you find the exact size of drill bits.

The whole process might take patience and a hell of a time. But if you once apply this trick you’ll learn a great deal of knowledge about the color of plugs and size of drill bits.


1. How do I choose the right size drill bit for a wall plug?

Experts suggest using a drill bit always smaller than the wall plug. But there is some difference too. For example, if there is a plastic plug for a concrete wall, then go with what experts have suggested already. But then again, for a steel-made anchor, you need to go against the suggestion of the experts slightly.

In this case, use a drill bit that has exactly the same size as the steel anchor. In case you are not able to find the exact size of the anchor, you can make it up with the smaller drill bit. For the extra area of a large hole, fill it with a coat made of baking soda and the superglue.

2. What size anchor do I need for a 3/8 drill bit?

As we have already said to get fit into an anchor, the size of the drill bit should be a little smaller than the size of the anchor. If you have a drill bit 3/8 of size then create a hole of ½ inches at least. Also, make sure the hole excels the length of the anchor to accomplish the job.

3. What size drill bit for a plastic anchor?

Plastic anchor has great elasticity and therefore, it requires drill bits that are exactly of its size. Also, smaller drill bits also will go with the plastic anchor. To create a perfect whole, first, take the measurement of the shank of the drill bits. Then take the measurement of the front of the required anchor.

After that, compare the two measurements and then create the whole following the diameter of the drill bit. You can choose a drill bit 1/16inches larger as it will not affect the creation of the whole for a plastic anchor.

4. What size drill bit for 8×40 anchor & 6×30 wall anchor drill bit size?

The appropriate size of drill bit for an 8×40 anchor would be the same as the measurement of the front of the anchor. In this case, the shank of the drill bit should also be the same in size. The equivalent sizes of the shank and the front of drill bits and anchors respectively are perfect. In alternative cases, 1/16inches drill bits are alright to fulfill the project as well.

For a 6×30 wall anchor, one would usually use a drill bit 15/64 inches of size. But this equivalent might not always fit the project. Most of the professionals suggest 1/4inches drill bits for 6×30 wall anchors. These sizes of wall anchor and drill bits go along with each other.

Last Updated on March 13, 2022 by Rogers Weber

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