Short answer: read the sidewall, figure out which size format it is, then check rim width. A two-number size like 6.00-9 is width and rim diameter. A three-number size like 21x8-9 is overall diameter, width and rim diameter. A press-on size like 21x8x15 is outside diameter, width and inside diameter. Those are not interchangeable.

Most tire calls we take start the same way. Someone walks out to the lift, looks at the sidewall and reads us a string of numbers. Sometimes it is clean, like 6.00-9. Sometimes it is 21x8-9. Sometimes the tire is so worn they can only make out half of it.

Getting the size right is the most important step in ordering a replacement forklift tire. Get it wrong and the tire will not fit, or it fits but sits wrong on the wheel. Either way the lift is down longer than it needs to be. Here are the size formats you will see on our site, what each one generally means, and how to double check before you order.

Why forklift tire sizes look so different

Forklift tires have been built by a lot of manufacturers over a lot of years. The industry never settled on one way to write a size. On our solid forklift tire and pneumatic forklift tire pages you will see several formats side by side:

  • Two-number sizes like 6.00-9, 7.00-12, 6.50-10 and 10.00-20.
  • Three-number sizes with an x like 21x8-9, 18x7-8, 23x9-10 and 27x10-12.
  • Metric style sizes like 200x50-10.
  • Press-on sizes like 21x8x15 and 21x5x15.

They all describe the same basic things: how big the tire is and what wheel or rim it fits. You just need to know which number is which.

Two-number sizes: 6.00-9, 7.00-12, 10.00-20

In a size like 6.00-9, the first number is generally the nominal section width. The last number is the rim diameter in inches. So a 6.00-9 fits a 9 inch rim. A 7.00-12 fits a 12 inch rim. A 10.00-20 fits a 20 inch rim.

This format is common on pneumatic style forklift tires. You will see it on both our air-filled and solid pneumatic lines. For example:

That is the whole idea of a solid pneumatic tire. It is made in pneumatic sizes so it fits a pneumatic forklift wheel.

Three-number sizes: 21x8-9, 18x7-8, 23x9-10

A size like 21x8-9 generally reads as overall diameter, then width, then rim diameter, all in inches. So a 21x8-9 is roughly a 21 inch tall tire, about 8 inches wide, on a 9 inch rim.

You will see this format on the 21x8-9 K Tread, the 18x7-8 M Tread, the 23x9-10 S Tread and the 27x10-12 S Tread.

Some sizes have a two-number equivalent and a three-number equivalent, and people use them interchangeably. Our pneumatic forklift line even lists an 18-7-8 tire, written with dashes instead of an x. If you see a size written two ways, do not guess which one is right. Read us exactly what is on the sidewall and we will sort it out.

Metric style sizes: 200x50-10

A size like 200x50-10 is a metric style designation. On our 200x50-10 K Tread, the last number is still the rim diameter in inches. If your lift came from overseas, or from a manufacturer that uses metric sizing, this is the format you will likely see.

Press-on sizes: 21x8x15 and 21x5x15

Press-on tires are a different setup. They are bonded to a steel band and pressed onto the wheel. Their size is usually written as outside diameter x width x inside diameter, all in inches.

So a 21X8X15 Duramax Smooth Tread Nonmarking press-on is about 21 inches tall, 8 inches wide, and fits a 15 inch band. The 21X5X15 Military Lug press-on has the same diameters but is narrower.

This is where people get burned. A press-on size and a pneumatic size are not interchangeable. A cushion tire lift and a pneumatic tire lift use different wheels. If your current tire is pressed onto a band, you need a press-on replacement. No exceptions.

Do not forget rim width

Two tires can have the exact same size and still not fit the same wheel. Some sizes are offered for more than one rim width.

We carry the 250-15 K Tread in a version built for a 7.00 rim width and a version for a 7.50 rim width. Same with the 10.00-20 S Tread, which we list for an 8 inch rim width. The 10.00-20 M Tread comes in two versions as well.

Rim width matters most with solid pneumatic tires, because there is no air holding the tire in shape. Know your rim width before you order.

How to find your size when the sidewall is worn

If you cannot read the sidewall, work through this list:

1. Check the other tires on the lift. The tire on the opposite side of the same axle should be the same size.

2. Look at the wheel. Many wheels have the rim size stamped on them.

3. Check the data plate or manual. Many lifts list their tire sizes in the operator manual.

4. Measure. Overall diameter, tread width and wheel diameter will get us close.

5. Call us. We have an extensive database of tire and wheel fitments for various machine types. Give us the make and model and we can help.

Front and rear are usually different

Most forklifts run a larger drive tire up front and a smaller steer tire in the back. Do not assume all four tires are the same. When you order, give us the size for each position.

Pneumatic, solid pneumatic or press-on?

Once you have the size, confirm what type of tire you are replacing.

  • Pneumatic tires like our Duramax Industrial Lug tube type forklift tires are air filled and require tubes.
  • Solid pneumatic tires like the Dureaco line fit the same pneumatic wheels, but are solid rubber.
  • Press-on tires fit a different style of wheel entirely.

If you are switching from pneumatic to solid pneumatic, the size will typically match. The solid tire is made in pneumatic sizes.

Practical takeaways

  • Read the sidewall out loud, exactly as written. Do not convert it in your head.
  • Know the format before you shop: two-number, three-number, metric or press-on.
  • Confirm rim width on any size we list more than once.
  • Get the size for every wheel position, not just one.
  • If anything is unclear, call before you order, not after the tire shows up.

FAQ

What does 6.00-9 mean on a forklift tire?

It generally means a tire with a 6.00 nominal section width that fits a 9 inch rim.

What does 21x8-9 mean?

It generally means about 21 inches overall diameter, about 8 inches wide, on a 9 inch rim.

Is 21x8x15 the same as 21x8-9?

No. 21x8x15 is a press-on size for a 15 inch band. 21x8-9 is a pneumatic style size for a 9 inch rim. They fit different wheels.

Why do some tires list a rim width?

Some sizes are made for more than one rim width. Pick the one that matches your wheel.

Can I just give you my forklift make and model?

Yes. We have an extensive fitment database, and our technical reps can help you select the right tire.

Still not sure? Ask us

The wrong size costs you time and freight, and it keeps a machine parked. If you have any doubt, contact us or call (909) 230-5552 before you order. Five minutes on the phone beats waiting on a tire that does not fit. You can also check our FAQ page for more answers.