Data sheet TS-275/70R18 · Size
275/70R18 in inches
275/70R18 is 33.2 in (842 mm) overall by the formula and makes 608 revs per mile (378 per km).
Fig. 1 — Cross-section
Table 1 — Nominal dimensions
| Item | in | mm |
|---|---|---|
| DOverall diameter | 33.16 | 842 |
| ASection width | 10.83 | 275 |
| BSidewall | 7.58 | 192.5 |
| CRim | 18 | 457.2 |
| Circumference | 104.2 | 2,646 |
| Revs per mile · km | 608 | 378 |
| Flotation size printed | 33X11.00R18LT | Mickey Thompson |
|---|---|---|
| Measuring rim | 8″ | Nitto LT |
| Approved rims | 7.0–8.5, 7.0–9.0, 7.0–8.0″ | 19 LT tires |
Table 2 — Measured range
33.19–33.62″overall diameter, 20 tires from 5 makers (math: 33.16″)
49–66 lbweight, 19 LT versions
13.5–20.0/32″new tread depth
3,640 lbmax load per tire, 14 of 19 LT versions list it, as published
19 LT · 1 Pversions in the makers’ tables we read
All 20 tires ↓Table 3
20 tires in 275/70R18, 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 33.16″. 20 tires from 5 makers measure 33.19″–33.62″. Tallest here: Nitto Trail Grappler M/T (mud-terrain), 33.62″. 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 125R | 33.19″ | — | 7.0–8.5 | 53.8 lb | 19.0/32″ | — |
| Nitto Ridge Grapplernittotire.com · Oct 15, 2026 | LT · E 125/122Q | 33.19″ | 10.98″ | 7.0–9.0 | 58.5 lb | 16.4/32″ | 3,640 lb @ 80 psi |
| Nitto Recon Grappler A/Tnittotire.com · Oct 15, 2026 | LT · E 125/122S | 33.19″ | 10.98″ | 7.0–9.0 | 54.3 lb | 15.9/32″ | 3,640 lb @ 80 psi |
| Firestone Destination X/Tfirestonetire.com · Oct 15, 2026 | LT · E 125S | 33.20″ | — | 7.0–8.5 | 50.3 lb | 16.0/32″ | — |
| Firestone Destination M/T2firestonetire.com · Oct 15, 2026 | LT · E 125Q | 33.20″ | — | 7.0–8.5 | 59.9 lb | 20.0/32″ | — |
| Firestone Transforce HT3firestonetire.com · Oct 15, 2026 | LT · E 125S | 33.20″ | — | 7.0–9.0 | 48.9 lb | 15.0/32″ | — |
| Firestone Transforce AT2firestonetire.com · Oct 15, 2026 | LT · E 125R | 33.20″ | — | 7.0–8.5 | 51.2 lb | 18.0/32″ | — |
| Kumho Road Venture AT52kumhotireusa.com · Oct 15, 2026 | LT · E 125/122S | 33.20″ | 11.00″ | 7.0–9.0 | 55.1 lb | 16.0/32″ | 3,640 lb @ 80 psi |
| Kumho Road Venture RTkumhotireusa.com · Oct 15, 2026 | LT · E 125/122R | 33.20″ | 11.00″ | 7.0–9.0 | 59.3 lb | 17.3/32″ | 3,640 lb @ 80 psi |
| Kumho Crugen HT51kumhotireusa.com · Oct 15, 2026 | LT · E 125/122R | 33.20″ | 10.50″ | 7.0–8.0 | 56.2 lb | 14.5/32″ | 3,640 lb @ 80 psi |
| Toyo Open Country A/T IIItoyotires.com · Oct 15, 2026 | LT · E 125/122S | 33.20″ | 11.00″ | 7.0–9.0 | 53.0 lb | 16.4/32″ | 3,640 lb @ 80 psi |
| Toyo Open Country R/T Trailtoyotires.com · Oct 15, 2026 | LT · E 125/122Q | 33.20″ | 11.00″ | 7.0–9.0 | 55.0 lb | 16.4/32″ | 3,640 lb @ 80 psi |
| Toyo Open Country H/T IItoyotires.com · Oct 15, 2026 | LT · E 125/122S | 33.20″ | 11.00″ | 7.0–8.5 | 53.0 lb | 14.6/32″ | 3,640 lb @ 80 psi |
| Nitto Dura Grapplernittotire.com · Oct 15, 2026 | LT · E 125/122R | 33.23″ | 11.00″ | 7.0–9.0 | 53.5 lb | 16.0/32″ | 3,640 lb @ 80 psi |
| Mickey Thompson Baja Legend MTZmickeythompsontires.com · Oct 15, 2026 | LT · E 125P | 33.30″ | 11.30″ | 7.0–9.0 | 60.0 lb | 20.0/32″ | 3,640 lb @ 80 psi |
| Kumho Road Venture MT71kumhotireusa.com · Oct 15, 2026 | LT · E 125/122Q | 33.40″ | 11.00″ | 7.0–8.5 | 66.4 lb | 19.0/32″ | 3,640 lb @ 80 psi |
| Mickey Thompson Baja Boss A/Tmickeythompsontires.com · Oct 15, 2026 | LT · E 125Q | 33.40″ | 10.80″ | 7.0–9.0 | 66.0 lb | 18.5/32″ | 3,640 lb @ 80 psi |
| Mickey Thompson Baja Legend EXPmickeythompsontires.com · Oct 15, 2026 | LT · E 125Q | 33.40″ | 11.00″ | 7.0–9.0 | 55.0 lb | 18.5/32″ | 3,640 lb @ 80 psi |
| Nitto Trail Grappler M/Tnittotire.com · Oct 15, 2026 | LT · E 125/122Q | 33.62″ | 11.10″ | 7.0–9.0 | 65.7 lb | 19.1/32″ | 3,640 lb @ 80 psi |
| Nitto Terra Grappler G3nittotire.com · Oct 15, 2026 | SL 116T | 33.19″ | 10.98″ | 7.0–9.0 | 45.6 lb | 13.5/32″ | 2,756 lb @ 44 psi |
§ 1
Nominal measurements
By the formula 275/70R18 measures 33.2 in (842 mm) overall. The section width is 10.8 in (275 mm) and the sidewall height is 7.6 in (193 mm).
The rim is 18 in (457 mm). Circumference is 104.2 in (2,646 mm). Revolutions per mile are 608 (378 per km). These are unloaded nominal numbers from the size math.
- Overall diameter: 33.2 in (842 mm).
- Section width: 10.8 in (275 mm).
- Sidewall height: 7.6 in (193 mm).
- Circumference: 104.2 in (2,646 mm); 608 revs per mile (378 per km).
§ 2
What makers publish
Tire makers' tables list 20 tires in 275/70R18 from 5 brands: Firestone, Nitto, Kumho, Toyo and Mickey Thompson. Nineteen are LT versions and one is a P-metric or passenger version; load ranges in the tables include SL and E.
Published overall diameters run from 33.19 in to 33.62 in, about +0.1% to +1.4% versus the formula number. Weights run from 45.6 lbs to 66.4 lbs. New tread depths run from 13.5/32 in to 20/32 in.
- Firestone Winterforce LT LT275/70R18 — diameter 33.19 in; weight 53.8 lbs; tread depth 19/32 in. (Firestone)
- Toyo Open Country A/T III LT275/70R18 — diameter 33.2 in; weight 53 lbs; tread depth 16.4/32 in; Toyo lists 626 revs per mile. (Toyo)
- Nitto Ridge Grappler LT275/70R18 — diameter 33.19 in; weight 58.5 lbs; tread depth 16.4/32 in. (Nitto)
§ 3
Close sizes and changes
Sizes within a ±3% overall-diameter window include 255/80R17 (33.1 in), 295/70R17 (33.3 in) and 33x11.50R17 (33.0 in). The ±3% window is a tire-shop rule of thumb, not a law or vehicle maker specification.
Small diameter differences change indicated speed and axle height by a few tenths of an inch and change revs per mile by a couple counts. Use the comparison tool to check specific neighbors on your rim size.
- To 255/80R17: diameter −0.3% (−0.09 in); at indicated 60 mph true speed becomes 59.8 mph; axle clearance −0.05 in; revs 608 → 610.
- To 295/70R17: diameter +0.3% (+0.10 in); at indicated 60 mph true speed becomes 60.2 mph; axle clearance +0.05 in; revs 608 → 606.
Fig. 2
275/70R18 and the sizes next to it
To scale, on one ground line. Diameter by the formula.
Table 4
Compare 275/70R18 with another size
Type any size: diameter, sidewall, speedometer and clearance change against this one.
Comparison
275/65R18 is 32.07″ tall, −3.27% against 275/70R18. At 60 mph on the dial you drive 58.0 mph.
| Item | 275/70R18 | 275/65R18 | Change |
|---|---|---|---|
| Overall diameter | 33.16″ | 32.07″ | −1.08″ −3.27% |
| Section width | 10.83″ | 10.83″ | 0.00″ |
| Sidewall | 7.58″ | 7.04″ | −0.54″ |
| Circumference | 104.2″ | 100.8″ | −3.4″ |
| Revs per mile | 608 | 629 | +21 |
| Axle height | 16.58″ | 16.04″ | −0.54″ |
When the odometer counts 1,000 miles, you have driven 967.3 miles.
Engine RPM at the same road speed: +3.4%. Gear ratio calculator
Speedometer
| Dial shows | True speed | Difference |
|---|---|---|
| 30 mph | 29.0 mph | −1.0 |
| 45 mph | 43.5 mph | −1.5 |
| 60 mph | 58.0 mph | −2.0 |
| 70 mph | 67.7 mph | −2.3 |
| 80 mph | 77.4 mph | −2.6 |
275/70R18275/65R18
Note 1
P-metric or LT in the same size
19 LT and 1 P versions in the tables we read.
No single model in our tables is published in both P and LT versions of 275/70R18; Table 3 lists both types side by side.
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 275/70R18: 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 275/70R18
Same rim or ±1″, diameter within 3%. A shop rule of thumb, not a law.
| Size | Diameter | Width | vs 275/70R18 | At 60 mph | Clearance |
|---|---|---|---|---|---|
| 255/80R17 | 33.06″ | 10.0″ | −0.3% | 59.8 | −0.05″ |
| 295/70R17 | 33.26″ | 11.6″ | +0.3% | 60.2 | +0.05″ |
| 33x11.50R17 | 33.00″ | 11.5″ | −0.5% | 59.7 | −0.08″ |
| 33x11.50R18 | 33.00″ | 11.5″ | −0.5% | 59.7 | −0.08″ |
| 33x12.50R17 | 33.00″ | 12.5″ | −0.5% | 59.7 | −0.08″ |
| 33x12.50R18 | 33.00″ | 12.5″ | −0.5% | 59.7 | −0.08″ |
| 325/60R18 | 33.35″ | 12.8″ | +0.6% | 60.4 | +0.10″ |
| 235/80R18 | 32.80″ | 9.3″ | −1.1% | 59.4 | −0.18″ |
| 285/70R17 | 32.71″ | 11.2″ | −1.4% | 59.2 | −0.22″ |
| 305/65R18 | 33.61″ | 12.0″ | +1.4% | 60.8 | +0.23″ |
Q&A
Common questions
How many revolutions per mile does 275/70R18 make?
By the formula 275/70R18 makes 608 revolutions per mile (378 per km).
Do makers publish different diameters for this size?
Yes. Makers' tables show overall diameters from 33.19 in to 33.62 in, which is about +0.1% to +1.4% larger than the formula number.
What load information should I check?
The tire sidewall shows the maximum load rating and, for LT tires, the load range letter (49 CFR 571.139). Also see the tire and loading placard on the driver's door jamb for vehicle-specific information (49 CFR 571.110).
Are there LT and passenger versions of 275/70R18?
Makers list 20 tires in this size: 19 LT versions and 1 P-metric or passenger version (maker size tables checked October 15, 2026).
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
- Nitto: size table (nittotire.com)checked Oct 15, 2026
- Kumho: size table (kumhotireusa.com)checked Oct 15, 2026
- Toyo: size table (toyotires.com)checked Oct 15, 2026
- Mickey Thompson: size table (mickeythompsontires.com)checked Oct 15, 2026
- Nitto: size table (nittotire.com)checked Oct 15, 2026
- Firestone: size table (firestonetire.com)checked Oct 15, 2026
- Firestone: size table (firestonetire.com)checked Oct 15, 2026
- Firestone: size table (firestonetire.com)checked Oct 15, 2026
- Firestone: size table (firestonetire.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.