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520/85R38 tire size

Tractor drive tire, about 73.5 in (1,868 mm) tall.

What 520/85R38 means

520 mm nominal section width, 85 aspect ratio, R radial, for a 38-inch rim.

Dimensions

Overall diameter
73.5 in (1,868 mm)
Static loaded radius
32.7 in (830 mm)
Rolling circumference
218.1 in (5,540 mm)
RCI group
46 (about 73 in tall, rolling circumference ≈ 219 in)

Continental Agricultural Tires Technical Databook (measured values) and the Firestone Rolling Circumference Index chart.

Equivalent sizes

Same height and width, same 38" rim: 20.8R38.

600 mm (24.5")
650/65R38

Same height, other width — keeps front axle lead/lag about the same; needs the right rim width.

Full conversion →

Sources: Continental Agricultural Tires Technical Databook, Firestone Ag RCI chart, Firestone hydroinflation tables. Checked October 2026. How we source data.

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