Off-Road & Truck Sizing
Flotation (Inches) to Metric Tire Converter
Looking for metric equivalents to classic 33", 35", or 37" off-road tires? Convert between inches and metric radials instantly.
Interactive Inch-to-Metric Tire Size Resolver
Target Diameter: 35.00" • Width: 12.50" (318 mm)
Closest Metric Radial Matches:
Common Truck Flotation Conversion Cheat Sheet
| Flotation Size | Metric Equivalent | True Diameter | Typical Lift Needed |
|---|---|---|---|
| 31x10.50R15 | 265/75R15 or 245/75R16 | 30.8" | Stock to 1" Level |
| 33x12.50R15 | 285/75R16 or 285/70R17 | 32.8" | 1.5" - 2.5" Leveling Kit |
| 35x12.50R17 | 315/70R17 or 305/70R18 | 34.8" | 2.5" - 3.5" Suspension Lift |
| 37x12.50R17 | 325/80R17 or 37x12.50R20 | 36.8" | 4.5" - 6.0" Full Lift |
How to Convert Flotation Inches to Metric Radials Manually
To convert a flotation tire like 35x12.50R17 into metric dimensions:
- Metric Width: Multiply width in inches by 25.4 (e.g. 12.50 × 25.4 = 317.5 mm ➔ 315 mm).
- Sidewall Height: (Overall Diameter − Rim Diameter) ÷ 2 = (35 − 17) ÷ 2 = 9.0 inches (228.6 mm).
- Aspect Ratio: (Sidewall Height ÷ Width) × 100 = (228.6 ÷ 317.5) × 100 = 71.9% (rounds to 70 series).
- Result: 315/70R17.
Flotation Scale Blueprint
Flotation Dimension Dynamics: Flotation tires measured by total outer diameter in inches (33", 35", 37") convert to metric radial section width (mm) and sidewall profile percentages.
Inch ➔ Metric
Frequently Asked Questions About Flotation vs Metric Tires
What is a 33x12.50 tire in metric size?
A 33x12.50 flotation tire is equivalent to a metric 285/75R16 or 285/70R17 (roughly 32.8" tall by 11.4" wide). If you want true 12-inch width, a 305/70R16 or 305/65R17 is the closest direct match.
What is a 35x12.50R17 in metric tire size?
A 35x12.50R17 converts directly to a 315/70R17 (34.4" tall by 12.4" wide). This size is the standard factory equipment on extreme off-road trucks such as the Ford F-150 Raptor and Ram TRX.
What is the difference between flotation and metric tire sizing?
Flotation sizing uses total physical dimensions in inches (Height × Width R Rim, e.g. 35x12.50R17). Metric sizing uses width in millimeters and sidewall height as a percentage aspect ratio (e.g. 315/70R17). Metric tires offer many more modern wheel diameter choices (18", 20", 22") and wider selections of heavy-duty E-load plies.
Do 35-inch tires actually measure a true 35 inches?
Almost never. Most brand-new 35x12.50 tires measure between 34.4" and 34.8" inflated at recommended cold PSI. Under the curb weight of a 5,000+ lb truck, the static loaded rolling radius equates to an effective working height of roughly 33.8 inches.