Data sheet TS-285/60R20 · Size

285/60R20 in inches

285/60R20 has a nominal 33.5 in overall diameter, an 11.2 in section width and a 6.7 in sidewall; it makes 603 revolutions per mile.

Fig. 1 — Cross-section

A section width, B sidewall, C rim, D overall diameter. Nominal, on the measuring rim.

Table 1 — Nominal dimensions

285/60R20: nominal dimensions in inches and millimeters
Item	in	mm
Overall diameter	33.46	850
Section width	11.22	285
Sidewall	6.73	171.0
Rim	20	508.0
Circumference	105.1	2,670
Revs per mile · km	603	374

From the makers’ size tables
Flotation size printed	34X11.50R20LT	Mickey Thompson
Measuring rim	8.5″	Nitto LT
Approved rims	8.5–10.0, 8.0–10.0″	14 LT tires

Table 2 — Measured range

33.46–33.90″overall diameter, 16 tires from 5 makers (math: 33.46″)

50–69 lbweight, 14 LT versions

13.6–18.9/32″new tread depth

3,640 lbmax load per tire, 11 of 14 LT versions list it, as published

14 LT · 2 Pversions in the makers’ tables we read

All 16 tires ↓

Table 3

16 tires in 285/60R20, as published

One row per model and type, from each maker’s size table. LT first, then P-metric; sorted by diameter.

The math says 33.46″. 16 tires from 5 makers measure 33.46″–33.90″. Tallest here: Mickey Thompson Baja Legend EXP (all-terrain), 33.90″. Check the maker’s number before you buy for a tight fit.

Published dimensions for 285/60R20
Tire	Type	Diameter	Width	Rims, in	Weight	Tread	Max load
Nitto Recon Grappler A/Tnittotire.com · Oct 15, 2026	LT · E 125/122S	33.46″	11.50″	8.5–10.0	59.9 lb	16.0/32″	3,640 lb @ 80 psi
Firestone Destination X/Tfirestonetire.com · Oct 15, 2026	LT · E 125S	33.50″	—	8.0–10.0	52.7 lb	16.0/32″	—
Firestone Transforce HT3firestonetire.com · Oct 15, 2026	LT · E 125R	33.50″	—	8.0–10.0	49.9 lb	15.0/32″	—
Firestone Transforce AT2firestonetire.com · Oct 15, 2026	LT · E 125R	33.50″	—	8.0–10.0	55.7 lb	16.0/32″	—
Kumho Road Venture AT52kumhotireusa.com · Oct 15, 2026	LT · E 125/122S	33.50″	11.50″	8.5–10.0	52.9 lb	16.0/32″	3,640 lb @ 80 psi
Kumho Road Venture RTkumhotireusa.com · Oct 15, 2026	LT · E 125/122R	33.50″	11.50″	8.5–10.0	61.8 lb	17.3/32″	3,640 lb @ 80 psi
Toyo Open Country A/T IIItoyotires.com · Oct 15, 2026	LT · E 125/122R	33.50″	11.50″	8.5–10.0	56.0 lb	16.5/32″	3,640 lb @ 80 psi
Toyo Open Country R/T Trailtoyotires.com · Oct 15, 2026	LT · E 125/122R	33.50″	11.50″	8.5–10.0	57.0 lb	16.5/32″	3,640 lb @ 80 psi
Toyo Open Country M/Ttoyotires.com · Oct 15, 2026	LT · E 125/122Q	33.50″	11.50″	8.0–10.0	69.0 lb	18.9/32″	3,640 lb @ 80 psi
Toyo Open Country H/T IItoyotires.com · Oct 15, 2026	LT · E 125/122R	33.50″	11.50″	8.0–10.0	59.0 lb	15.8/32″	3,640 lb @ 80 psi
Mickey Thompson Baja Boss A/Tmickeythompsontires.com · Oct 15, 2026	LT · E 125Q	33.60″	11.30″	8.0–10.0	67.0 lb	18.5/32″	3,640 lb @ 80 psi
Nitto Ridge Grapplernittotire.com · Oct 15, 2026	LT · E 125/122Q	33.70″	11.50″	8.5–10.0	61.6 lb	16.4/32″	3,640 lb @ 80 psi
Nitto Trail Grappler M/Tnittotire.com · Oct 15, 2026	LT · E 125/122Q	33.70″	11.50″	8.5–10.0	67.4 lb	18.9/32″	3,640 lb @ 80 psi
Mickey Thompson Baja Legend EXPmickeythompsontires.com · Oct 15, 2026	LT · E 125Q	33.90″	11.40″	8.0–10.0	62.0 lb	18.5/32″	3,640 lb @ 80 psi
Nitto Terra Grappler G3nittotire.com · Oct 15, 2026	SL 116T	33.46″	11.50″	8.0–10.0	48.9 lb	13.6/32″	2,756 lb @ 44 psi
Toyo Open Country A/T IIItoyotires.com · Oct 15, 2026	SL 116T	33.50″	11.50″	8.0–10.0	48.0 lb	13.6/32″	2,756 lb @ 44 psi

§ 1

Nominal dimensions and revs

By the formula the nominal overall diameter is 33.5 in (850 mm). The section width is 11.2 in (285 mm) and the sidewall height is 6.7 in (171 mm). Rim diameter is 20 in (508 mm); circumference is 105.1 in (2,670 mm) and revolutions per mile are 603 (374 per km).

§ 2

Published measurements and specs

Makers' size tables list 16 tires in 285/60R20 from 5 brands, with 14 LT and 2 P-metric versions. Published overall diameters run from 33.46 in to 33.9 in; published weights run from 48 lbs to 69 lbs and new tread depths from 13.6/32 in to 18.9/32 in.

Examples: Nitto lists the Recon Grappler A/T LT285/60R20 at 33.46 in diameter, 59.9 lbs and 16/32 in tread depth. Toyo lists the Open Country A/T III LT285/60R20 at 33.5 in, 56 lbs, 16.5/32 in tread depth and 621 revs per mile. Mickey Thompson lists the Baja Boss LT285/60R20 at 33.6 in, 67 lbs, 18.5/32 in and the equivalent 34X11.50R20LT. Makers publish approved rim widths and maximum loads on their tables as required by 49 CFR 571.139.

§ 3

Closest sizes and effects

The neighbor tables use a ±3% overall-diameter window; that window is a tire-shop rule of thumb, not a law. Sizes within the window include 305/55R20 (33.2 in, −0.8%) and 33x11.50R20 (about 33.0 in, −1.4%).

Example effects: swapping to 305/55R20 reduces diameter by 0.26 in (−0.8%), so an indicated 60 mph would be about 59.5 mph, revolutions per mile go 603 → 607 and axle ground clearance changes by −0.13 in (−3 mm). Swapping to 33x11.50R20 reduces diameter by 0.46 in (−1.4%), so an indicated 60 mph reads about 59.2 mph and revolutions per mile go 603 → 611. Use the speedometer calculator or the size comparison to see other neighbors and numeric effects.

305/55R20: 33.2 in (−0.8%) — indicated 60 mph ≈ 59.5 mph; revs 603 → 607.
33x11.50R20: ~33.0 in (−1.4%) — indicated 60 mph ≈ 59.2 mph; revs 603 → 611.

Fig. 2

285/60R20 and the sizes next to it

To scale, on one ground line. Diameter by the formula.

Table 4

Compare 285/60R20 with another size

Type any size: diameter, sidewall, speedometer and clearance change against this one.

Comparison

295/60R20 is 33.94″ tall, +1.41% against 285/60R20. At 60 mph on the dial you drive 60.8 mph.

285/60R20 vs 295/60R20
Item	285/60R20	295/60R20	Change
Overall diameter	33.46″	33.94″	+0.47″ +1.41%
Section width	11.22″	11.61″	+0.39″
Sidewall	6.73″	6.97″	+0.24″
Circumference	105.1″	106.6″	+1.5″
Revs per mile	603	594	−8
Axle height	16.73″	16.97″	+0.24″

When the odometer counts 1,000 miles, you have driven 1,014.1 miles.

Engine RPM at the same road speed: −1.4%. Gear ratio calculator

Speedometer

Speedometer reading and true speed
Dial shows	True speed	Difference
30 mph	30.4 mph	+0.4
45 mph	45.6 mph	+0.6
60 mph	60.8 mph	+0.8
70 mph	71.0 mph	+1.0
80 mph	81.1 mph	+1.1

285/60R20295/60R20

Note 1

P-metric or LT in the same size

Toyo Open Country A/T III is published in both versions.

Toyo Open Country A/T III, 285/60R20: P and LT
Toyo Open Country A/T III	P · 116T	LT · E · 125/122R
Overall diameter	33.50″	33.50″
Max load	2,756 lb @ 44 psi	3,640 lb @ 80 psi
Weight	48.0 lb	56.0 lb
Tread depth	13.6/32″	16.5/32″
Approved rims	8.0–10.0″	8.5–10.0″

Source: Toyo size table, checked Oct 15, 2026. On trucks and SUVs, the load ratings of the tires on an axle must add up to at least the axle’s GAWR on the certification label (49 CFR 571.110).

Vehicles on 285/60R20: not listed yet. We add a vehicle here only from its maker’s own spec sheet for that year and trim.

The size your vehicle left the factory on is printed on the tire and loading placard on the driver’s door jamb (49 CFR 571.110). Pressure and load: that placard too.

Table 5

Within 3% of 285/60R20

Same rim or ±1″, diameter within 3%. A shop rule of thumb, not a law.

Sizes within 3% of 285/60R20
Size	Diameter	Width	vs 285/60R20	At 60 mph	Clearance
305/55R20	33.21″	12.0″	−0.8%	59.5	−0.13″
33x11.50R20	33.00″	11.5″	−1.4%	59.2	−0.23″
33x12.50R20	33.00″	12.5″	−1.4%	59.2	−0.23″
275/60R20	32.99″	10.8″	−1.4%	59.2	−0.24″
295/60R20	33.94″	11.6″	+1.4%	60.8	+0.24″
34x11.50R20	34.00″	11.5″	+1.6%	61.0	+0.27″
275/65R20	34.07″	10.8″	+1.8%	61.1	+0.31″
295/55R20	32.78″	11.6″	−2.1%	58.8	−0.34″
265/60R20	32.52″	10.4″	−2.8%	58.3	−0.47″

Other 20″ sizes

Q&A

Common questions

How big is 285/60R20 in inches?

By the formula 285/60R20 is 33.5 in overall diameter, 11.2 in section width and 6.7 in sidewall, making 603 revolutions per mile.

Do makers list different diameters for 285/60R20?

Yes. Makers' tables show published diameters from 33.46 in to 33.9 in, published weights from 48 lbs to 69 lbs and new tread depths from 13.6/32 in to 18.9/32 in.

Where is tire and vehicle loading information shown?

The tire sidewall shows the maximum load rating and, for LT tires, the load range letter as required by 49 CFR 571.139. The vehicle's recommended cold tire pressures are on the tire and loading placard on the driver's door jamb per 49 CFR 571.110.

Will a nearby size change my speedometer reading?

Yes. Small diameter differences within the ±3% rule change indicated speed by fractions of a mile per hour. For example, 305/55R20 makes an indicated 60 mph read about 59.5 mph and 33x11.50R20 about 59.2 mph.

Notes

Method and sources

Each number and rule comes from a source with the date it was checked.

Sidewall = width × aspect ratio ÷ 100
Diameter = rim × 25.4 + 2 × sidewall (mm)
Revs per mile = 63,360 ÷ (π × diameter, in)
True speed = dial × new diameter ÷ old diameter
Clearance change = half the diameter change

Numbers are nominal: the tire unloaded, on its measuring rim. Revs per mile published by makers run higher than the formula. “Within 3%” is a rule of thumb tire shops use, not a law. Tire pressure: the placard on your door jamb.

Nitto: size table (nittotire.com)checked Oct 15, 2026
Toyo: size table (toyotires.com)checked Oct 15, 2026
Mickey Thompson: size table (mickeythompsontires.com)checked Oct 15, 2026
49 CFR 571.139 (FMVSS No. 139), S5.5(d)ecfr.gov · checked Oct 15, 2026
49 CFR 571.110 (FMVSS No. 110), S4.3ecfr.gov · checked Oct 15, 2026

Calculators and size classes

33″22 metric and 11 flotation sizes measure 32.5–33.5″ by the formula305/70R16 · 285/75R16 · 295/75R16 · 305/65R17 · 285/70R17 35″15 metric and 16 flotation sizes measure 34.5–35.5″ by the formula315/75R16 · 325/65R18 · 305/70R18 · 285/75R18 · 285/65R20 37″3 metric and 13 flotation sizes measure 36.5–37.5″ by the formula385/70R16 · 315/80R17 · 375/45R24