The Correct Way to Measure Binder Rings

What are you putting in your 3-ring binder?

Find out how many pages and other materials will go in your binder before you make any other decisions. This will clarify ring size, which gives a pretty good idea of what style of binder, which 3-ring mechanism you will need and how strong your binder has to be. Knowing the page count of your materials (and whether it varies) is key to determining ring size. Adding pamphlets, samples or give-aways, USB drives or other objects lets you know how large the spine of the binder might need to be.

What size of materials are you putting in your binder? US standard paper is 8.5″ by 11″ and most binders you find in the United States hold that. But maybe your materials are based off a half-sized sheet – then you will want to look into a compact binder to match your paper size. Europe and some of Canada use A4 size paper. Other factors about your content size you’d want to consider is whether you are using a standard U.S. paper size but in landscape (sideways). This changes how your binder is set up and you’d need to look into oblong formats.

How many sheets of paper does a binder ring hold?

This depends on what style of ring you choose. A D-ring and a round ring hold the paper differently and have different benefits.

D-ring binders

In a D-ring, the paper is held evenly on the right side, meaning that your tab dividers all line up and there is a clean line of paper. Some people find it harder to turn the pages in a D-ring binder compared to a round ring (though a slant D-ring solves this problem). A D-ring always mounts on the back panel of a binder – not the spine – so the paper rests on the flat part of the ring when it is closed. This makes the cover a little wider.

If you want a small ring, it helps to know that there is no 1/2″ D-ring.

• 3/4″ D-ring holds up to 150 sheets of paper
• 1″ D-ring holds up to 220 sheets of paper
• 1.5″ D-ring holds up to 350 sheets of paper
• 2″ D-ring holds up to 450 sheets of paper
• 2.5″ D-ring holds up to 550 sheets of paper

Round ring binders (O-ring)

A round ring can mount on the spine of a binder, so the covers, front and back, are a little shorter than with a ring that mounts on the back panel. It is easy to turn pages since there is a continuous curve. The issue with seeing tab dividers towards the bottom of the stack of information is negligible in smaller rings and up to you to decide of it is an issue in large rings. A lot of people don’t see it as a problem.

For people with small paper needs: you can get a 1/2″ O-ring binder!

• 3/4″ O-ring holds up to 130 sheets of paper
• 1″ O-ring holds up to 170 sheets of paper
• 1.5″ O-ring holds up to 250 sheets of paper
• 2″ O-ring holds up to 350 sheets of paper
• 2.5″ O-ring holds up to 450 sheets of paper

How do you measure the binder ring size?

Here is how the correct way to measure varies for the two ring styles.

Measuring a D-ring

Looking at the D-ring find the flat part of the D shape and measure ONLY the flat part, not the curves top and bottom.

Measuring an O-ring

Just to be confusing, this ring measures from the base of the ring (the rings are set in a bar) to the middle of the ring where it closes: the diameter of the ring. But make sure you measure top to bottom as it is the most accurate way.

Now that you’ve got an idea on what style and size of rings best suit your needs, it is time to browse through all the fun customizing options that’ll make your binder stand out. For more design ideas visit our project gallery.