8.25-20 Tire Conversion Chart | What Fits Next

This older 20-inch numeric tire size usually stays on the same rim first; 9.00-20 is a step up, not a true equal.

The tricky part with an 8.25-20 tire is that people often want one neat modern match, but the market doesn’t always give you one. On older tractors, wheel excavators, forklifts, and trailers, this size can sit in a gray area between old numeric listings and newer metric or radial listings. That means the right swap starts with fit, not with a catchy cross-reference.

If your machine already runs well on 8.25-20, the safest path is still the same size on the same rim. When that exact size is hard to find, you can branch into nearby sizes, but only after you check outside diameter, section width, rim width, load rating, speed symbol, and clearance at full lock or full suspension travel.

Why This Older Size Trips People Up

Old numeric tire sizes look simple. An 8.25-20 tells you the tire is built for a 20-inch rim, and the “8.25” points to its nominal section width in inches. That sounds plain enough. The trouble starts when you try to swap that old code into a newer bias, radial, or metric size name.

Brand to brand, an 8.25-20 can shift more than many buyers expect. Tread pattern, carcass build, ply rating, and the rim actually used all change the final mounted shape. Two tires can wear the same size name and still differ enough to create rubbing, gearing drift, steering heaviness, or a nose-high stance on the machine.

That’s why a conversion chart should be read as a starting point. It gets you into the right neighborhood. It does not give every machine a free pass to bolt on the next size and roll out the gate.

What The Size Name Tells You

With 8.25-20, the easiest part is the rim diameter. The tire is built around a 20-inch wheel. The less neat part is the width number. In an old numeric system, that width is nominal, not a promise that every mounted tire will measure the same with every tread and every casing build.

That’s why old-size conversions work best when you treat the size name as a label first, then verify the real mounted numbers. In plain terms, you want the true outside diameter and the true section width from the spec sheet, not just the molded size on the sidewall.

Where Buyers Usually Go Wrong

The most common mistake is jumping straight from 8.25-20 to 9.00-20 because both are easy to find. That jump can work on some machines. It can also create a tire that is taller, wider, and heavier than the original setup was built around.

Another miss is assuming a metric size must exist just because many newer tires use metric naming. In industrial listings, that direct one-to-one match often isn’t there. A few charts skip a straight metric twin for 8.25-20 and instead show nearby sizes that sit above it or below it in rolling radius.

How To Read An 8.25-20 Tire Conversion Chart

Read it in this order: rim size, outside diameter, section width, then load rating. That order keeps you from buying a tire that mounts but still rubs, steers poorly, or changes the machine’s stance.

On official industrial tables, 8.25-20 is often shown on a 6.5-20 rim. In Trelleborg’s industrial manual, 8.25-20 appears as its own size on a 6.5-20 rim, while 9.00-20 is the size that pairs with 270/95-20 in the alternative-size column. That tells you something useful right away: 270/95-20 tracks with 9.00-20 in that chart, not with 8.25-20. You can see that on the Trelleborg industrial technical manual.

That same “check the real numbers” rule shows up in actual product sheets. On Camso’s wheel-excavator line, 8.25-20 is listed on a 6.50 rim, with 7.00 as an alternate rim. In that line, the tire sits well below 9.00-20 in both width and overall diameter. The Camso WEX 752 spec sheet makes that gap easy to see.

Size You’ll See	How Close It Usually Is	What To Check Before You Buy
8.25-20	Exact size name match	Best first choice when you want original fit and stance
8.25R20	Same labeled size, radial build	Check real mounted width, load, and casing shape
8.3-20	Near-name farm listing in some markets	Check tread style and true diameter before treating it as equal
9.00-20	One clear step larger	Check clearance, steering feel, and paired tire height
270/95-20	Often tied to 9.00-20, not 8.25-20	Do not treat it as a direct swap without measurements
210/90R20	Smaller radius family in ag charts	Useful only after checking your machine’s use and rim
215/95R20	Larger radius family in ag charts	Usually closer to the next size up than to 8.25-20
Custom metric choice	Possible on some machines	Match outside diameter, width, rim, and load before ordering

What The Real Measurements Say

This is where a conversion chart turns from guesswork into something you can trust. In Camso’s WEX 752 data, an 8.25-20 is listed at 38.6 inches overall diameter and 9.6 inches section width on a 6.50 rim, with 7.00 shown as an alternate. The same sheet lists 9.00-20 at 40.3 inches overall diameter and 10.4 inches section width. That is not a tiny jump. It is a visible step up in both height and width.

Camso’s WL sheet lands in the same ballpark. There, 8.25-20 is listed at 39.4 inches overall diameter and 9.9 inches section width, while 9.00-20 lands at 40.9 inches and 10.5 inches. Different tread families, same lesson: a 9.00-20 is bigger in real life, not just on paper.

So if you’re trying to keep axle height, steering stop clearance, or front-to-rear stance close to stock, 9.00-20 should be treated as a size jump, not a clean conversion.

When A Larger Swap Still Makes Sense

There are cases where stepping up works. Maybe the machine has plenty of clearance. Maybe you want a bit more ground clearance. Maybe the old size is scarce in your market, while 9.00-20 is on the shelf at a sane price. In those cases, the jump can be worth it.

But do the boring checks first. Check dual spacing if the axle runs pairs. Check the gap to tie rods, knuckles, fenders, loader arms, and brake lines. Check the load rating against the work the machine really does. Also check whether you need the same rolling radius on both sides of a drive axle or on all four corners of a four-wheel-drive setup.

Checks That Matter More Than The Name On The Sidewall

If you only keep one rule in your head, make it this: numeric tire conversion is a fit check, not a name swap. The chart gets you close. The spec sheet closes the deal.

Check	Why It Matters	What A Miss Can Cause
Rim width	Controls tire shape and mounted width	Crown wear, poor bead seat, odd handling
Overall diameter	Sets ride height and rolling radius	Rubbing, stance change, speed error
Section width	Sets side clearance	Fender or frame contact
Ply rating or load index	Sets load ability	Heat, damage, short life
Speed symbol	Sets safe road pace	Overheating on transport runs
Tube type or tubeless	Changes wheel and valve needs	Air loss or mounting issues
Tread pattern	Shapes traction and wear	Poor grip or rough ride
Pair match	Keeps axle heights even	Pulling, odd wear, drive stress

Which Size Usually Ends Up Being The Best Buy

If you want the least drama, buy another 8.25-20. That keeps the machine closest to its original fit and keeps your clearance math simple. If you find an 8.25R20 from a line that fits your load and rim, that can also be a clean answer, but check the mounted specs first.

If you’re eyeing 9.00-20, treat it like a mild upsizing project. It may fit. It may even work well. But it is not a no-thought conversion. The same caution applies to 270/95-20. In official industrial charts, that size sits with 9.00-20, not with 8.25-20.

A Simple Ordering Method

• Read the old sidewall and wheel size.
• Write down rim width, not just rim diameter.
• Pull the spec sheet for the tire you want to buy.
• Match overall diameter as closely as you can.
• Match section width to your real clearance.
• Match load and speed to the machine’s work.
• Replace in pairs if the axle setup calls for it.

That routine takes a few extra minutes, but it saves you from the usual mess: a tire that mounts fine, then scrubs at full turn, lifts one end of the machine, or wears in a shape you didn’t bargain for.

Get The Conversion Right The First Time

An 8.25-20 tire conversion chart is most useful when you read it with a tape measure and a spec sheet nearby. The old size does not always have a neat modern twin. In many cases, the best match is still 8.25-20 itself. The next common move, 9.00-20, is a real size jump, not a direct equal.

So start with the original size. If stock is thin or you want a new direction, compare real diameter, real width, rim width, and load data before you buy. That slower, cleaner check is what keeps the machine working the way it should.