Data sheet TS-275/65R18 · Size
275/65R18 in inches
275/65R18 measures 32.1 in (815 mm) overall by the formula and turns 629 revolutions per mile (391 per km). Use the door-jamb placard for inflation and load information.
Fig. 1 — Cross-section
Table 1 — Nominal dimensions
| Item | in | mm |
|---|---|---|
| DOverall diameter | 32.07 | 815 |
| ASection width | 10.83 | 275 |
| BSidewall | 7.04 | 178.8 |
| CRim | 18 | 457.2 |
| Circumference | 100.8 | 2,559 |
| Revs per mile · km | 629 | 391 |
| Flotation size printed | 32X11.00R18LT | Mickey Thompson |
|---|---|---|
| Measuring rim | 8″ | Nitto LT |
| Approved rims | 7.5–9.0, 8.0–9.5, 6.5–8.0″ | 16 LT tires |
Table 2 — Measured range
32.09–32.40″overall diameter, 28 tires from 5 makers (math: 32.07″)
45–64 lbweight, 16 LT versions
10.0–20.0/32″new tread depth
3,415 lbmax load per tire, 11 of 16 LT versions list it, as published
16 LT · 12 Pversions in the makers’ tables we read
All 28 tires ↓Table 3
28 tires in 275/65R18, 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 32.07″. 28 tires from 5 makers measure 32.09″–32.40″. Tallest here: Mickey Thompson Baja Boss A/T (all-terrain), 32.40″. Check the maker’s number before you buy for a tight fit.
| Tire | Type | Diameter | Width | Rims, in | Weight | Tread | Max load |
|---|---|---|---|---|---|---|---|
| Firestone Winterforce LTfirestonetire.com · Oct 15, 2026 | LT · E 123R | 32.09″ | — | 7.5–9.0 | 52.2 lb | 19.0/32″ | — |
| Nitto Ridge Grapplernittotire.com · Oct 15, 2026 | LT · E 123/120Q | 32.09″ | 10.98″ | 8.0–9.5 | 56.4 lb | 16.4/32″ | 3,415 lb @ 80 psi |
| Nitto Terra Grappler G3nittotire.com · Oct 15, 2026 | LT · E 123/120S | 32.09″ | 10.98″ | 8.0–9.5 | 51.3 lb | 15.9/32″ | 3,415 lb @ 80 psi |
| Nitto Dura Grapplernittotire.com · Oct 15, 2026 | LT · E 123/120Q | 32.09″ | 10.98″ | 8.0–9.5 | 55.1 lb | 16.8/32″ | 3,415 lb @ 80 psi |
| Firestone Destination X/Tfirestonetire.com · Oct 15, 2026 | LT · E 123S | 32.10″ | — | 7.5–9.0 | 49.5 lb | 16.0/32″ | — |
| Firestone Destination M/T2firestonetire.com · Oct 15, 2026 | LT · E 123Q | 32.10″ | — | 7.5–9.0 | 55.0 lb | 20.0/32″ | — |
| Firestone Transforce HT3firestonetire.com · Oct 15, 2026 | LT · E 123S | 32.10″ | — | 7.5–9.0 | 45.5 lb | 15.0/32″ | — |
| Firestone Transforce AT2firestonetire.com · Oct 15, 2026 | LT · E 123R | 32.10″ | — | 7.5–9.0 | 48.3 lb | 16.0/32″ | — |
| Kumho Road Venture AT52kumhotireusa.com · Oct 15, 2026 | LT · E 123/120S | 32.10″ | 11.00″ | 8.0–9.5 | 53.1 lb | 16.0/32″ | 3,415 lb @ 80 psi |
| Kumho Road Venture RTkumhotireusa.com · Oct 15, 2026 | LT · E 123/120R | 32.10″ | 11.00″ | 8.0–9.5 | 58.2 lb | 17.3/32″ | 3,415 lb @ 80 psi |
| Kumho Crugen HT51kumhotireusa.com · Oct 15, 2026 | LT · E 123/120R | 32.10″ | 9.80″ | 6.5–8.0 | 52.9 lb | 14.5/32″ | 3,415 lb @ 80 psi |
| Toyo Open Country A/T IIItoyotires.com · Oct 15, 2026 | LT · E 123/120S | 32.10″ | 11.00″ | 8.0–9.5 | 52.0 lb | 16.4/32″ | 3,415 lb @ 80 psi |
| Toyo Open Country H/T IItoyotires.com · Oct 15, 2026 | LT · E 123/120S | 32.10″ | 11.00″ | 7.5–9.0 | 52.0 lb | 14.5/32″ | 3,415 lb @ 80 psi |
| Kumho Road Venture MT71kumhotireusa.com · Oct 15, 2026 | LT · E 123/120Q | 32.30″ | 11.00″ | 7.5–9.0 | 63.9 lb | 19.0/32″ | 3,415 lb @ 80 psi |
| Mickey Thompson Baja Legend EXPmickeythompsontires.com · Oct 15, 2026 | LT · E 123Q | 32.30″ | 11.00″ | 7.5–9.5 | 53.0 lb | 18.5/32″ | 3,415 lb @ 80 psi |
| Toyo Open Country M/Ttoyotires.com · Oct 15, 2026 | LT · E 123/120P | 32.30″ | 11.00″ | 7.5–9.0 | 63.0 lb | 18.9/32″ | 3,415 lb @ 80 psi |
| Nitto Ridge Grapplernittotire.com · Oct 15, 2026 | XL 116T | 32.09″ | 10.98″ | 7.5–9.5 | 45.0 lb | 13.5/32″ | 2,756 lb @ 50 psi |
| Nitto Terra Grappler G3nittotire.com · Oct 15, 2026 | SL 116T | 32.09″ | 10.98″ | 7.5–9.5 | 42.0 lb | 13.5/32″ | 2,756 lb @ 44 psi |
| Firestone Destination A/T2firestonetire.com · Oct 15, 2026 | SL 116T | 32.10″ | — | 7.5–9.5 | 39.2 lb | 12.0/32″ | — |
| Firestone Destination LE3firestonetire.com · Oct 15, 2026 | SL 116T | 32.10″ | — | 7.5–9.5 | 38.1 lb | 10.0/32″ | — |
| Firestone Destination LE4firestonetire.com · Oct 15, 2026 | SL 116T | 32.10″ | — | 7.5–9.5 | 38.0 lb | 12.0/32″ | — |
| Kumho Road Venture AT52kumhotireusa.com · Oct 15, 2026 | SL 116T | 32.10″ | 11.00″ | 7.5–9.5 | 41.7 lb | 13.5/32″ | 2,756 lb @ 51 psi |
| Kumho Crugen HT51kumhotireusa.com · Oct 15, 2026 | SL 114T | 32.10″ | 9.80″ | 6.5–7.5 | 40.8 lb | 12.0/32″ | 2,601 lb @ 51 psi |
| Kumho Crugen Premiumkumhotireusa.com · Oct 15, 2026 | SL 114T | 32.10″ | 11.00″ | 7.0–9.5 | 43.1 lb | 11.0/32″ | 2,601 lb @ 51 psi |
| Toyo Open Country A/T IIItoyotires.com · Oct 15, 2026 | SL 116T | 32.10″ | 11.00″ | 7.5–9.5 | 42.0 lb | 13.5/32″ | 2,756 lb @ 44 psi |
| Toyo Open Country R/T Trailtoyotires.com · Oct 15, 2026 | XL 116T | 32.10″ | 11.00″ | 7.5–9.5 | 42.0 lb | 13.5/32″ | 2,756 lb @ 50 psi |
| Toyo Open Country H/T IItoyotires.com · Oct 15, 2026 | SL 116T | 32.10″ | 11.00″ | 7.5–9.5 | 43.0 lb | 12.1/32″ | 2,756 lb @ 44 psi |
| Mickey Thompson Baja Boss A/Tmickeythompsontires.com · Oct 15, 2026 | SL 116T | 32.40″ | 10.90″ | 7.5–9.5 | 46.0 lb | 16.0/32″ | 2,756 lb @ 44 psi |
§ 1
Nominal measurements
32.1 in (815 mm) overall diameter by the formula. Section width 10.8 in (275 mm). Sidewall height 7.0 in (179 mm). Rim 18 in (457 mm).
Circumference 100.8 in (2,559 mm). Revolutions per mile 629 (391 per km). These are unloaded nominal numbers calculated from the size formula.
§ 2
Published measurements
Tire makers list 28 tires in 275/65R18 from 5 brands. Sixteen are LT versions and 12 are P-metric or passenger versions. Makers list load ranges SL, XL and E on some tires. Firestone, Nitto, Kumho, Toyo and Mickey Thompson appear in the tables.
Published overall diameters run from 32.09 in to 32.4 in against 32.07 in by the formula (0.0% to +1.0%). Published weights run from 38 lbs to 63.9 lbs. New tread depths run from 10/32 in to 20/32 in.
- Firestone Winterforce LT: 32.09 in overall; weight 52.2 lbs; tread depth 19/32 in (Firestone).
- Toyo Open Country A/T III: 32.1 in overall; weight 52 lbs; maker lists 647 revolutions per mile (Toyo).
- Mickey Thompson Baja Legend EXP: 32.3 in overall; weight 53 lbs; tread depth 18.5/32 in (Mickey Thompson).
§ 3
Closest sizes and effects
The neighbor table uses a ±3% overall-diameter window on near rims. The ±3% window is a tire-shop rule of thumb, not a law. See the comparison tool for other sizes.
Two close neighbors: 255/75R17 at 0.0% and 275/70R17 at +0.3%. At an indicated 60 mph the 255/75R17 reads 60.0 mph true; ground clearance at the axle changes by −0.01 in. At an indicated 60 mph the 275/70R17 reads 60.2 mph true; axle clearance changes by +0.04 in. Use the speedometer calculator to check other pairs.
- Nearby sizes within ±3% include 255/75R17, 255/70R18, 275/70R17 and 305/60R18.
- The ±3% guideline is a shop rule of thumb, not a vehicle maker specification.
Fig. 2
275/65R18 and the sizes next to it
To scale, on one ground line. Diameter by the formula.
Table 4
Compare 275/65R18 with another size
Type any size: diameter, sidewall, speedometer and clearance change against this one.
Comparison
275/70R18 is 33.16″ tall, +3.38% against 275/65R18. At 60 mph on the dial you drive 62.0 mph.
| Item | 275/65R18 | 275/70R18 | Change |
|---|---|---|---|
| Overall diameter | 32.07″ | 33.16″ | +1.08″ +3.38% |
| Section width | 10.83″ | 10.83″ | 0.00″ |
| Sidewall | 7.04″ | 7.58″ | +0.54″ |
| Circumference | 100.8″ | 104.2″ | +3.4″ |
| Revs per mile | 629 | 608 | −21 |
| Axle height | 16.04″ | 16.58″ | +0.54″ |
When the odometer counts 1,000 miles, you have driven 1,033.8 miles.
Engine RPM at the same road speed: −3.3%. Gear ratio calculator
Speedometer
| Dial shows | True speed | Difference |
|---|---|---|
| 30 mph | 31.0 mph | +1.0 |
| 45 mph | 46.5 mph | +1.5 |
| 60 mph | 62.0 mph | +2.0 |
| 70 mph | 72.4 mph | +2.4 |
| 80 mph | 82.7 mph | +2.7 |
275/65R18275/70R18
Note 1
P-metric or LT in the same size
Nitto Ridge Grappler is published in both versions.
| Nitto Ridge Grappler | P · 116T | LT · E · 123/120Q |
|---|---|---|
| Overall diameter | 32.09″ | 32.09″ |
| Max load | 2,756 lb @ 50 psi | 3,415 lb @ 80 psi |
| Weight | 45.0 lb | 56.4 lb |
| Tread depth | 13.5/32″ | 16.4/32″ |
| Approved rims | 7.5–9.5″ | 8.0–9.5″ |
Source: Nitto 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 275/65R18: 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 275/65R18
Same rim or ±1″, diameter within 3%. A shop rule of thumb, not a law.
| Size | Diameter | Width | vs 275/65R18 | At 60 mph | Clearance |
|---|---|---|---|---|---|
| 255/75R17 | 32.06″ | 10.0″ | 0.0% | 60.0 | −0.01″ |
| 255/70R18 | 32.06″ | 10.0″ | −0.1% | 60.0 | −0.01″ |
| 275/70R17 | 32.16″ | 10.8″ | +0.3% | 60.2 | +0.04″ |
| 235/80R17 | 31.80″ | 9.3″ | −0.8% | 59.5 | −0.14″ |
| 305/60R18 | 32.41″ | 12.0″ | +1.0% | 60.6 | +0.17″ |
| 265/70R17 | 31.61″ | 10.4″ | −1.5% | 59.1 | −0.23″ |
| 265/65R18 | 31.56″ | 10.4″ | −1.6% | 59.0 | −0.26″ |
| 285/65R18 | 32.59″ | 11.2″ | +1.6% | 61.0 | +0.26″ |
| 265/70R18 | 32.61″ | 10.4″ | +1.7% | 61.0 | +0.27″ |
| 305/65R17 | 32.61″ | 12.0″ | +1.7% | 61.0 | +0.27″ |
Q&A
Common questions
How big is 275/65R18 in inches?
Nominal overall diameter is 32.1 in (815 mm) by the formula and it makes 629 revolutions per mile (391 per km).
Will a different size change my speedometer?
Yes. Small diameter changes alter true speed. For example, 275/70R17 is +0.3% and would make an indicated 60 mph read about 60.2 mph true; use the speedometer calculator to compare other sizes.
What load and inflation info do I need?
See the tire and loading placard on the driver's door jamb for the vehicle maker’s recommended cold inflation pressure. The tire sidewall shows the maximum load rating and, for LT tires, the load range letter (49 CFR 571.139 and 49 CFR 571.110).
How many brands and models use this size?
Tire makers’ tables list 28 tires in 275/65R18 from 5 brands, with published diameters from 32.09 in to 32.4 in and load ranges SL, XL and E.
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.
- Firestone: size table (firestonetire.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
Related
Calculators and size classes
- Tire size calculatorTwo sizes: diameter, sidewall, revs and speedometer.
- Compare up to 4 sizesUp to four sizes side by side, drawn to scale.
- Metric ↔ inchesMetric to inches, and 33x12.50R20 to metric.
- Speedometer errorTrue speed after a size change.
- Gear ratio and RPMEngine RPM and the ratio to regear to.
- Wheel offset and pokeBackspacing, poke and inner clearance.
- DOT date codeHow old a tire is, from the DOT number.
- Load index chartLoad index in pounds and kilograms.
- Bolt patternMeasure it, convert inches to mm.
- Rim size and tire fitWhat 17x8 ET35 means, which sizes go on it.
- What fits my carStart from the placard on the door.
- Tire size chartCommon sizes in inches, by rim.