Data sheet TS-305/70R17 · Size
305/70R17 in inches
305/70R17 measures 33.8 in (859 mm) overall diameter by the formula. It has a nominal section width 12.0 in (305 mm) and a sidewall 8.4 in (214 mm).
Fig. 1 — Cross-section
Table 1 — Nominal dimensions
| Item | in | mm |
|---|---|---|
| DOverall diameter | 33.81 | 859 |
| ASection width | 12.01 | 305 |
| BSidewall | 8.41 | 213.5 |
| CRim | 17 | 431.8 |
| Circumference | 106.2 | 2,698 |
| Revs per mile · km | 596 | 371 |
| Measuring rim | 9″ | Nitto LT |
|---|---|---|
| Approved rims | 8.0–9.5, 8.0–10.0″ | 5 LT tires |
Table 2 — Measured range
33.81–33.90″overall diameter, 5 tires from 3 makers (math: 33.81″)
58–69 lbweight, 5 LT versions
16.0–16.8/32″new tread depth
3,195–3,970 lbmax load per tire, 4 of 5 LT versions list it, as published
5 LT · 0 Pversions in the makers’ tables we read
All 5 tires ↓Table 3
5 tires in 305/70R17, 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 33.81″. 5 tires from 3 makers measure 33.81″–33.90″. Tallest here: Toyo Open Country A/T III (all-terrain), 33.90″. Check the maker’s number before you buy for a tight fit.
| Tire | Type | Diameter | Width | Rims, in | Weight | Tread | Max load |
|---|---|---|---|---|---|---|---|
| Firestone Destination X/Tfirestonetire.com · Oct 15, 2026 | LT · E 121R | 33.81″ | — | 8.0–9.5 | 58.4 lb | 16.0/32″ | — |
| Nitto Ridge Grapplernittotire.com · Oct 15, 2026 | LT · E 121/118Q | 33.86″ | 12.24″ | 8.0–10.0 | 68.6 lb | 16.4/32″ | 3,195 lb @ 65 psi |
| Nitto Recon Grappler A/Tnittotire.com · Oct 15, 2026 | LT · E 125/122R | 33.86″ | 12.24″ | 8.0–10.0 | 64.4 lb | 16.3/32″ | 3,640 lb @ 65 psi |
| Nitto Terra Grappler G3nittotire.com · Oct 15, 2026 | LT · F 128/125R | 33.86″ | 12.24″ | 8.0–10.0 | 63.3 lb | 16.3/32″ | 3,970 lb @ 80 psi |
| Toyo Open Country A/T IIItoyotires.com · Oct 15, 2026 | LT · E 121/118R | 33.90″ | 12.20″ | 8.0–10.0 | 64.0 lb | 16.8/32″ | 3,195 lb @ 65 psi |
§ 1
Size by the formula
The numbers below are the nominal, unloaded values by the size formula.
By the formula the overall diameter is 33.8 in (859 mm). The section width is 12.0 in (305 mm). The sidewall height is 8.4 in (214 mm). The rim is 17 in (432 mm). Circumference is 106.2 in (2,698 mm). Revolutions per mile are 596 revs per mile (371 per km).
§ 2
What makers publish
Tire makers list five tires in 305/70R17 from three brands, all LT and no P-metric passenger versions. Makers list load ranges E and F.
Published overall diameters run from 33.81 in to 33.9 in against 33.81 in by one formula table. Weights in makers' tables run from 58.4 lbs to 68.6 lbs. New tread depths run from 16/32 in to 16.8/32 in.
- Firestone Destination X/T LT305/70R17 — overall diameter 33.81 in; weight 58.4 lbs; tread depth 16/32 in; approved rims 8.0–9.5 in.
- Nitto Ridge Grappler LT305/70R17 — overall diameter 33.86 in; overall width inflated 12.24 in; weight 68.6 lbs; tread depth 16.4/32 in.
- Toyo Open Country A/T III LT305/70R17 — overall diameter 33.9 in; overall width inflated 12.2 in; weight 64 lbs; tread depth 16.8/32 in; Toyo lists 614 revs per mile.
§ 3
Closest sizes and effects
For any other size, use the tire size comparison. The ±3% window is a tire-shop rule of thumb, not a law.
Two common neighbors within that window show very small changes to speedometer and ground clearance. Below are the computed differences for 285/75R17 and 285/70R18.
- 285/75R17: diameter +0.1% (+0.02 in, +1 mm); indicated 60 mph → true 60.0 mph; revolutions per mile 596 → 596; ground clearance at the axle +0.01 in (0 mm).
- 285/70R18: diameter −0.3% (−0.10 in, −3 mm); indicated 60 mph → true 59.8 mph; revolutions per mile 596 → 598; ground clearance at the axle −0.05 in (−1 mm).
Fig. 2
305/70R17 and the sizes next to it
To scale, on one ground line. Diameter by the formula.
Table 4
Compare 305/70R17 with another size
Type any size: diameter, sidewall, speedometer and clearance change against this one.
Comparison
315/70R17 is 34.36″ tall, +1.63% against 305/70R17. At 60 mph on the dial you drive 61.0 mph.
| Item | 305/70R17 | 315/70R17 | Change |
|---|---|---|---|
| Overall diameter | 33.81″ | 34.36″ | +0.55″ +1.63% |
| Section width | 12.01″ | 12.40″ | +0.39″ |
| Sidewall | 8.41″ | 8.68″ | +0.28″ |
| Circumference | 106.2″ | 108.0″ | +1.7″ |
| Revs per mile | 596 | 587 | −10 |
| Axle height | 16.91″ | 17.18″ | +0.28″ |
When the odometer counts 1,000 miles, you have driven 1,016.3 miles.
Engine RPM at the same road speed: −1.6%. Gear ratio calculator
Speedometer
| Dial shows | True speed | Difference |
|---|---|---|
| 30 mph | 30.5 mph | +0.5 |
| 45 mph | 45.7 mph | +0.7 |
| 60 mph | 61.0 mph | +1.0 |
| 70 mph | 71.1 mph | +1.1 |
| 80 mph | 81.3 mph | +1.3 |
305/70R17315/70R17
Note 1
P-metric or LT in the same size
5 LT and 0 P versions in the tables we read.
No single model in our tables is published in both P and LT versions of 305/70R17; 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 305/70R17: 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 305/70R17
Same rim or ±1″, diameter within 3%. A shop rule of thumb, not a law.
| Size | Diameter | Width | vs 305/70R17 | At 60 mph | Clearance |
|---|---|---|---|---|---|
| 285/75R17 | 33.83″ | 11.2″ | +0.1% | 60.0 | +0.01″ |
| 285/70R18 | 33.71″ | 11.2″ | −0.3% | 59.8 | −0.05″ |
| 34x10.50R17 | 34.00″ | 10.5″ | +0.6% | 60.3 | +0.09″ |
| 305/65R18 | 33.61″ | 12.0″ | −0.6% | 59.6 | −0.10″ |
| 255/85R17 | 34.07″ | 10.0″ | +0.8% | 60.5 | +0.13″ |
| 295/75R16 | 33.42″ | 11.6″ | −1.2% | 59.3 | −0.19″ |
| 295/70R18 | 34.26″ | 11.6″ | +1.3% | 60.8 | +0.22″ |
| 325/60R18 | 33.35″ | 12.8″ | −1.4% | 59.2 | −0.23″ |
| 295/70R17 | 33.26″ | 11.6″ | −1.6% | 59.0 | −0.28″ |
| 315/70R17 | 34.36″ | 12.4″ | +1.6% | 61.0 | +0.28″ |
Q&A
Common questions
How big is a 305/70R17?
By the formula the nominal overall diameter is 33.8 in (859 mm) and the section width is 12.0 in (305 mm).
How many revolutions per mile does 305/70R17 make?
By the formula 305/70R17 makes 596 revs per mile (371 per km). Toyo lists 614 revs per mile for its Open Country A/T III in this size.
Are there LT and passenger versions of 305/70R17?
Size tables list five tires in 305/70R17 and all five are LT versions; none are listed as P-metric passenger tires.
Where do I find the tire's load and recommended inflation?
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 manufacturer's recommended cold inflation pressures are on the tire and loading placard on the driver's door jamb (49 CFR 571.110).
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
- Toyo: size table (toyotires.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.