The Truth Between B11 VS E12

B11s and E12s seem to confuse many. Don’t worry. We understand the confusion! Allow us to help clear some things up for you today.

There are already many different lighting systems, light sources, fixtures, and so much more! Now, there are also codes to worry about too! Who knew light bulbs could be so complicated?

Well, you need not worry! Allow us to help you with this concern. Today, let’s talk about B11 VS E12. Are B11 and E12 Bulbs Interchangeable? Let’s found out right now!

B11 VS E12: Are the Two Interchangeable?

Well, the answer is not that simple. It’s a little more complicated than a yes or a no. To better help understand why that is, let’s define the two codes first.

What Does B11 Mean?

Let’s break this code down to understand better what it means.

First, we have the alphabetical component, which is a B. Second, we have the numerical part, which is an 11.

The B stands for the shape of the bulb, while the number refers to the diameter. The B stands for bullet or blunt tip. However, don’t be surprised if you hear others call this shape type by another name. For one, B-shaped bulbs are more commonly known as candelabra bulbs.

On the other hand, 11 means the bulb is exactly 1.375 inches in diameter. You might be asking how did this number come about.

Well, the answer lies in that light bulb sizes are computed by eights of an inch. So, for this particular size, you’ll half 11 by 8, which, in turn, will give you 1.375 inches.

When you’re looking at the bulb shape and size, you’re often considering the aesthetics of your lighting system. There are times you’ll have to look into the bulb shape and size for functionality purposes. However, usually, bulb shapes and sizes are interchangeable.

With that, as you might have guessed, there are many different light bulb shapes and sizes available. Some of the most common ones would be:

  • A19s: The A stands for arbitrary. These bulb shapes are often for home use.
  • G30s: The G stands for globe. These bulb shapes are another one that is often for home use. Compared with arbitrary bulbs, you can say that they are a little more aesthetic.
  • MR16s: The MR stands for multifaceted reflector. Unlike the first two examples we’ve shown you, multifaceted reflectors might be more known for outdoor use.

Of course, since there are common choices, you can expect not-so-common options as well. However, you do not have to worry. B11 bulbs are one of the most common options. You won’t have that much of a hard time looking for B11 bulbs.

Now, let’s go and talk about E12s. Before we continue, though, you must remember that B11 refers to the light bulb shape and size.

What Does E12 Mean?

What Does E12 Mean

Again, let’s break this code down first.

First, we have the alphabetical component, which is an E. Second, we have the numerical part, which is a 12.

After reading through the description of B11s, you might be thinking that the E would pertain to the bulb shape, and the 12 would refer to the diameter. If you did, you’re right and wrong. The E does not pertain to the light bulb shape, but the 12 does refer to the diameter.

The E is short for Edison. Thomas Edison. The founder and developer of the standard Edison screw base. As you can guess then, E stands for the screw base.

On the other hand, 12 does pertain to diameter. However, it’s a lot more simple than the computation of the bulb shape size. 12 stands for 12 millimeters.

Now, if you’re looking at the base, you’re considering the functionality of your light bulb. You usually can’t have an unfit bottom. Otherwise, it might not even work.

Some bases are interchangeable. However, unlike bulb shapes, the bottom is not as flexible. In other words, you often have to consider the socket first before you go ahead and pick your light bulb shape.

There are many bulb shapes and sizes. With that, you can expect that there are many base shapes and sizes too. Here are some of the ones you might see:

  • GU10: It is what you could call a spotlight bulb. It might be an ideal choice if you need directional lighting.
  • B15: Don’t be confused! The B here stands for bayonet. It is much more common in the automotive scene in the UK.

Again, if there are common choices, there are also not-so-common options (e.g., E30 bulbs). However, again, there’s nothing to worry about with E12 bulbs. Again, these bulbs are one of the most common options. You won’t have that much of a hard time looking for E12 bases.

Before we continue, again, keep in mind that E12 refers to the light bulb base and its size.

The Difference Between B11 and E12

Before we go back to the question, let’s quickly look at some of the differences between the two.







Known Names

Bullet Tip, Blunt Tip, Candelabra Bulbs

Edison Screw Base


 Presented in Inches

 Presented In Millimeters


 In Eights of an Inch

 As Is


Often for Aesthetic Purposes

 Often for Practical Purposes



B11 and E12 Are Not Interchangeable

Now, let’s go back to the question we’re trying to answer today.

If we look back at the definition of the two, or even just the table we’ve shown you above, you can see that B11s and E12s are different and not interchangeable. However, that’s because they are not on the same plane at all!

As you’ve seen above, one pertains to the light bulb’s shape, while the other refers to the base.

Getting a B11 and E12 Bulb

Getting a B11 and E12 Bulb

With all that, let’s address the elephant in the room. You don’t have to choose between the two. You can have the two in the same bulb.

The only time you might have to choose between the two is if no light bulb has both of these characteristics. In that instance, you’d have to make a decision.

B11 E12 light bulbs are usually for decorative use. It does make sense if one wants to consider the bulb shape first. However, before making anything look good, we have to secure that it is working first. Otherwise, it might all be a waste.

When you can’t have the two, you could try looking for alternatives. Here are some fill-ins for the two codes. As we said above, you can most likely interchange B11 with any other bulb shape and size. On the other hand, you might want to look for a C7 if no E12 is available.

Make Use of Adapters

Now, if the shape of the light bulb is of importance, there is another way around this problem. You can use adapters! Hopefully, though, you’re only filling in a few sockets.

Getting adapters for each bulb could get expensive. It is still better to try and find a light bulb that will fit in your sockets and satisfy your aesthetic needs if you could.

Other Things to Keep in Mind with B11 and E12 Bulbs

B11 VS E12 Are the Two Interchangeable

You are now hopefully well-acquainted with B11 and E12 bulbs. However, allow us to share a few more things before you leave.

Strategical Placing

As discussed above, B11 light bulbs are usually for decorative purposes. If you’re after illumination, they might not be the best choice. They will give you light, alright.

With their size, though, you can expect them to shed that much light. You might have to get a few together in one place for them to be as bright as you want them to be.

The Additional Letter

You might have found yourself shopping for some lights. However, you might have noticed that some options have an additional letter after the number. Now, you might be wondering what it means?

Well, if you happen to see an extra letter, it would pertain to the length of the bulb. Not every light bulb includes this feature in the production description, though. Usually, it’s only one of two letters – S or L. As you might have guessed, it simply means short or long.

Summary of The Truth Between B11 VS E12: Are B11 and E12 Bulbs Interchangeable?

Today, we uncovered the truth between B11s and E12s. Understandably, these codes would confuse many. However, the confusion mainly comes from thinking that the two are on the same plane.

As you’ve seen today, the two are very different in many respects. They are not interchangeable because they’re not even in the same category! The truth is, you can even get a B11 E12 bulb!

We hope we were able to shine a light on this concern. If you are still in the dark with some other LED matters, then you might want to give our other bright ideas a visit! We’ll be happy to have you around!

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