305/55R20 Tire Size: 33.2" Tall, a 33-Inch Tire
Straight answer
A 305/55R20 stands 33.2 inches tall and 12.0 inches wide on a 20-inch wheel, which makes it a 33-inch tire in truck-speak. NTW stocks 24 tire models in this size right now.
305/55R20 dimensions
Overall diameter
33.21"
Section width
12.01"
Sidewall height
6.60"
Wheel diameter
20"
Circumference
104.3"
Revolutions per mile
607
≈ 33.2x12.0R20 flotation. Nominal math; real tires run a few tenths off depending on brand, load range, rim width, and air pressure.
What 305/55R20 means
- 305Section width: 305 mm (12.0") wall to wall
- 55Aspect ratio: sidewall is 55% of the width, so 6.6" tall
- RRadial construction
- 20Fits a 20-inch wheel
Want the full rundown on sidewall codes, load index, and speed rating? Read how to read a tire size.
305/55R20 compared to nearby 20-inch sizes
Speedometer column assumes your truck is calibrated for 305/55R20 and reads 65 mph.
| Size | Height | vs 305/55R20 | Width change | Actual speed | Compare |
|---|---|---|---|---|---|
| 285/55R20 | 32.3" | -0.9" (-2.6%) | -0.8" | 63.3 mph | Full comparison |
| 275/60R20 | 33.0" | -0.2" (-0.7%) | -1.2" | 64.6 mph | Full comparison |
| 33x12.50R20 | 33.0" | -0.2" (-0.6%) | +0.5" | 64.6 mph | Full comparison |
| 295/60R20 | 33.9" | +0.7" (+2.2%) | -0.4" | 66.4 mph | Full comparison |
| 275/65R20 | 34.1" | +0.9" (+2.6%) | -1.2" | 66.7 mph | Full comparison |
Rule of thumb: inside 3% of stock diameter feels stock; past 8 to 10% and most owners budget for a re-gear. Run your exact numbers in the tire size calculator, or check what stepping down to 285/55R20 does.
Tires in stock in 305/55R20
24 models, 31 SKUs at NTW (different load ranges and sidewall styles). Refreshed daily.
| Tire | Type | Options | From |
|---|---|---|---|
| Toyo Open Country R/T | All Terrain | 3 | $443 |
| Falken Wildpeak A/T4W | All Terrain | 2 | $437 |
| Nitto Ridge Grappler | All Terrain | 2 | $454 |
| Nitto Terra Grappler G3 | All Terrain | 2 | $405 |
| Toyo Open Country R/T Trail | All Terrain | 2 | $431 |
| Venom Power Terra Hunter RT Plus | All Terrain | 2 | $295 |
| AMP Off-Road AT Terrain Attack | All Terrain | 1 | $299 |
| AMP Off-Road Mud Terrain Attack MT | Mud Terrain | 1 | $337 |
| AMP Off-Road Terrain Attack R/T | All Terrain | 1 | $362 |
| AMP Off-Road Terrain Pro AT | All Terrain | 1 | $289 |
| Avix Off-Road TRAILTEK R/T | All Terrain, Mud Terrain, On/Off-Road | 1 | $329 |
| Bfgoodrich All-Terrain T/A KO3 | All Terrain | 1 | $529 |
| Falken Rubitrek A/T | All Terrain | 1 | $430 |
| Falken Wildpeak M/T | Mud Terrain | 1 | $531 |
| Falken Wildpeak R/T01 | All Terrain | 1 | $557 |
| Mickey Thompson Baja Boss | Mud Terrain | 1 | $528 |
| Mickey Thompson Baja Boss AT | All Terrain | 1 | $503 |
| Mickey Thompson Baja Legend EXP | All Terrain | 1 | $453 |
| Mickey Thompson Baja Legend MTZ | Mud Terrain | 1 | $480 |
| Nitto EXO Grappler | All Terrain | 1 | $444 |
| Nitto Recon Grappler A/T | All Terrain | 1 | $479 |
| Nitto Trail Grappler M/T | Mud Terrain | 1 | $509 |
| Toyo Open Country A/T III | All Terrain | 1 | $521 |
| Toyo Open Country M/T | Mud Terrain | 1 | $546 |
Prices per tire at NTW when last checked; confirm at checkout.
Frequently Asked Questions
How tall is a 305/55R20 tire in inches?+
A 305/55R20 is 33.21 inches tall and 12.01 inches wide, with a 6.60-inch sidewall on a 20-inch wheel. Real mounted tires vary a few tenths of an inch by brand, load range, and rim width.
Is 305/55R20 a 33-inch tire?+
Close enough that everybody calls it one. It measures 33.2 inches, so it's sold and talked about as a 33. The flotation equivalent is 33.2x12.0R20.
What does 305/55R20 mean?+
305/55R20 means a tire 305 millimeters wide with a sidewall 55% as tall as it is wide, built for a 20-inch wheel.
305/55R20 vs 295/60R20: how much bigger?+
295/60R20 is 0.7 inches taller (2.2%) and 0.4 inches narrower. Going from 305/55R20 to 295/60R20, a speedometer reading 65 mph means you're actually doing 66.4.
Looking for another size? See the full truck tire size chart.