Metric-to-Flotation Tire Converter
Convert a metric tire size like 285/70 R17 into flotation inches (33x11.2R17). Get exact and nearest standard flotation sizes.
Express nominal dimensions in inches.
Metric-to-Flotation Tire Converter: Tire Size Inputs
Compare two tire sizes here. Use the formulas and reference tables below for this tool's specific calculation.
How Metric-to-Flotation Tire Converter Works?
The Metric-to-Flotation Tire Converter works by calculating the metric tire's overall diameter and section width in inches and writing them in diameter × width R rim form. The conversion takes 3 steps.
Enter the metric size
Type a size such as 285/70 R17.
Convert to inches
The converter returns an overall diameter of 32.71 in and a section width of 11.22 in.
Format the result
The converter writes the exact equivalent as 32.7x11.22R17 and the nearest common flotation size as 33x11.00R17.
Metric-to-Flotation Tire Converter Formula
The Metric-to-Flotation Tire Converter formula is D_in = (2 × W × AR ÷ 100) ÷ 25.4 + Rim and W_in = W ÷ 25.4.
D_in = 2 × W × AR ÷ 2,540 + RimW_in = W ÷ 25.4D_in x W_in R Rim- W
- Metric section width (mm)
- AR
- Metric aspect ratio (%)
- D_in, W_in
- Flotation diameter and width (in)
Worked example
A 315/70 R17 tire has a diameter of 2 × 315 × 70 ÷ 2,540 + 17 = 34.36 in (872.8 mm) and a width of 315 ÷ 25.4 = 12.40 in. The flotation equivalent is 34.4x12.40R17, which the market sells as a 34-inch or 35-inch class tire.
Metric-to-Flotation Tire Converter Conversion Table
The Metric-to-Flotation Tire Converter conversion table expresses 9 common metric truck sizes in flotation inches.
| Metric size | Diameter | Width | Exact flotation | Rounded flotation |
|---|---|---|---|---|
| 265/70 R17 | 31.61 in | 10.43 in | 31.6x10.43R17 | 32x10.50R17 |
| 285/70 R17 | 32.71 in | 11.22 in | 32.7x11.22R17 | 33x11.00R17 |
| 285/75 R16 | 32.83 in | 11.22 in | 32.8x11.22R16 | 33x11.00R16 |
| 305/70 R17 | 33.81 in | 12.01 in | 33.8x12.01R17 | 34x12.00R17 |
| 315/70 R17 | 34.36 in | 12.40 in | 34.4x12.40R17 | 34x12.50R17 |
| 285/65 R18 | 32.59 in | 11.22 in | 32.6x11.22R18 | 33x11.00R18 |
| 295/70 R18 | 34.26 in | 11.61 in | 34.3x11.61R18 | 34x11.50R18 |
| 275/65 R20 | 34.07 in | 10.83 in | 34.1x10.83R20 | 34x11.00R20 |
| 305/55 R20 | 33.21 in | 12.01 in | 33.2x12.01R20 | 33x12.00R20 |
What is Metric-to-Flotation Tire Converter?
A Metric-to-Flotation Tire Converter is a tool that rewrites a metric tire size in the inch format used for off-road and truck tires. Truck owners describe tires by height, such as a 33-inch tire, and metric codes hide that height.
Metric sizes land between flotation sizes. A 285/70 R17 tire is 32.7 in tall, so the market calls it a 33-inch tire, and the tire stands 0.3 in (7.6 mm) shorter than a true 33x12.50R17.
The converter gives exact decimal values for clearance math and rounded values for shopping.
What are the uses of Metric-to-Flotation Tire Converter?
There are 4 main uses of the Metric-to-Flotation Tire Converter, including lift kit matching and forum comparisons.
Lift kit matching
Match a metric tire to the inch height a lift kit supports.
Forum comparisons
Translate metric sizes into the inch sizes off-road communities use.
Clearance math
Use decimal inch height in fender trimming calculations.
Shopping
Find metric sizes that compete with a given flotation size.
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