12.4-24 Tractor Tires

Buying 12.4-24 tractor tires

12.4-24 is a rear tire for compact and small utility tractors. It is about 12.4 inches (315 mm) wide on a 24-inch wheel. It is common on tractors used for mowing, loader work, snow removal and small-acreage farming. It is a common size on tractors in this class.

The radial equivalents are 12.4R24 and 320/85R24. Most compact tractors run bias tires, which are cheaper and stiff enough to keep a loader steady.

R-1, R-3 or R-4?

Compact tractors come with three tread options, and 12.4-24 is made in more than one:

• R-1 ag: best traction in dirt, mud and snow, but hard on lawns.
• R-4 industrial: a middle ground for loader work on gravel and hard ground.
• R-3 turf: protects grass, but slips in mud.

Our tread types guide explains the differences. On a four-wheel-drive compact, changing the rear tread or size also changes the front-to-rear ratio, so change the fronts with the rears.

What to check

• Loader weight: match or exceed your current ply rating.
• Used tires: ask for the tread depth and photos. Compact tires often age out before they wear out, so check the date code.

Send us the quantity, tread type and delivery location for a quote.

What else is 12.4-24 called?

The same tire is written 12.4-24, 12.4×24, 12.4/24 or 12.4 24. All mean a bias-ply tire 12.4 in (315 mm) wide for a 24 in (610 mm) rim. The radial version is 12.4R24, and the usual metric radial match is 320/85R24. Do not confuse 12.4-24 with 12.00-24 or 1200-24, which are different sizes. Check the sidewall of the tire you are replacing before you order.

How does 12.4-24 compare with the other 24 in rim sizes?

On a 24 in rim, the number before the dash sets the width, and the height rises with it. These nominal figures use the standard size formula, with an 85% aspect ratio for old inch sizes, so real tires vary by make.

A real tire lands close to the formula. For example, Tires-Easy lists a 6-ply Carlisle R-1 in 12.4-24 at 45.67 in overall diameter, on an 11 in wide rim, carrying 2,400 lb (1,089 kg) at 24 psi. That is a single maker’s figure, not the size, so use your tire’s own data for load and pressure.

Can you swap 12.4-24 for 13.6-24 or a radial?

You can, but the new tire is taller. Moving from 12.4-24 to 13.6-24 adds about 2 in (51 mm) of height on paper, which changes ground speed and, on a front-wheel-assist tractor, the front-to-rear ratio. Check fender and axle clearance, keep both rears the same, and run the numbers in the lead-lag calculator and the tire size converter first. A radial 320/85R24 is nearly the same height as a bias 12.4-24, so it is the cleaner upgrade.

Bias or radial for 12.4-24?

For regular field work, a radial costs more but puts a longer footprint on the ground. For loader work, rocky ground or low yearly hours, a bias 12.4-24 is cheaper and tougher in the sidewall. See the radial vs bias guide for the break-even.

What do 12.4-24 tires cost on our site?

We list 11 models in 12.4-24. 10 have a listed price, from $235 (Petlas TA60) to $700 (Cultor AS-Agri 19) per tire, with a median of $429. Prices are per tire in US dollars and change with stock and season.

How tall is the 12.4-24 tire?

The nominal overall diameter is about 45.1 in (1,145 mm), which gives a rolling circumference near 142 in (3,597 mm). That figure is an estimate that assumes an 85% aspect ratio, the usual rule for old inch sizes. Real tires vary by make and load, so treat it as a guide and use the tire diameter calculator or the lead-lag calculator before you change size on a front-wheel-assist tractor.

Is 12.4-24 a radial or a bias tire?

It is a bias-ply size. The dash in the size marks bias construction, which costs less and has stiffer sidewalls. See the radial vs bias guide.