Metric to Flotation Tire Converter

Tires use two different sizing systems — metric (e.g. 235/75R15) and flotation (e.g. 31x10.50R15) — and the Metric to Flotation Tire Converter translates between them so you can cross-shop or swap tires with confidence. Select your conversion direction, then enter either your metric section width, aspect ratio, and rim diameter or your flotation overall diameter, section width, and rim diameter to get the converted tire size. Secondary outputs include overall diameter, section width, sidewall height, circumference, and revolutions per mile. Also try the calculate Recommended Rotation Interval, Time-Based Interval & Expected Rotations Per Year — Tire Rotation Interval.

Conversion Direction *

mm
%
inches
inches

Results

Converted Tire Size

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Overall Diameter

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Section Width

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Sidewall Height

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Circumference

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Revolutions per Mile

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Metric to Flotation Tire Converter gives you the most precise way to compare tire sizes across different sizing systems—making it simple to find exact equivalents for your vehicle or off-road SUV, crossover, or passenger car. Need to match flotation tires to a metric size (or vice versa)? This tool provides the insights you need to swap tires between wheel assemblies or vehicles, ensure fitment, or source hard-to-find replacements without missteps. When you care about maintaining the right diameter, tread width, and ride quality, converting tire sizing formats accurately is vital—especially for off-pavement or performance builds where a small difference can make all the difference.

Understanding Metric Tire Conversion: Metric vs Flotation Sizing Details

What is Metric Tire Sizing? (tire sizes, metric tire sizes)

Modern cars, crossovers, and SUVs usually use metric tire sizes, which follow a pattern like 265/75R16. Understanding this system helps you use any metric tire conversion tool or chart:

  • 265 – Tire’s width in millimeters (tread width)
  • 75 – Aspect ratio; sidewall height is 75% of the width
  • R – Radial construction
  • 16Wheel diameter in inches (fits only 16-inch wheels)
How to Read Tire Size

Example: A 265/75R16 tire is 265 mm wide, the sidewall height is 75% of 265 mm, and it fits a 16-inch wheel. Multiply and convert as needed for your calculation. The vertical section is key for understanding the relationship between width and aspect ratio.

How Flotation Tire Sizes Differ (standard tire sizes, flotation sizing, standard sizes)

Flotation sizing—such as 31x10.50R15—are common on older pickups, lifted off-pavement vehicles, and 4x4s. The sequence shows:

  • 31 – Approximate overall diameter in inches
  • 10.50Tread width in inches
  • R – Radial tire
  • 15 – Fits 15-inch rim
Why This Matters?

Flotation sizing is seen on lifted vehicles, older models, and classic pickups. Not all brands publish both metric and flotation for a specific option; metric to flotation tire converter tools help you find a compatible replacement or upgrade.

Why Convert Between Metric and Flotation? (tire conversion, convert, find tire sizes)

  • To find metric tire size equivalents for hard-to-locate flotation options
  • When replacing tires on vehicles that have swapped different size wheels or wheel assemblies
  • For off-pavement or 4x4 YJ wheels builds requiring precise fitment and clearance
  • Matching existing tires when only one sizing system is available at your store or location

Metric to Flotation Tire Converter & Tire Conversion Chart: Wheel Diameter Guide

Conversion Chart by 8-Inch Wheels (wheel, wheels, tire size, diameter)

P-MetricFlotationOutside Diameter (in)
205/75R818x8.50-818.0
215/60R818x9.50-818.2
225/75R819x8.50-819.0

Conversion Chart by 10-Inch Wheels (wheel size, tire sizes, diameter)

P-MetricFlotationOutside Diameter (in)
205/65R1020.5x8.00-1020.5
225/75R1022x11.00-1022.0
245/75R1024x8.50-1024.0

Conversion Chart by 16-Inch Wheels (metric tire sizes, standard tire sizes, tire conversion)

P-MetricFlotationOutside Diameter (in)
265/75R1631x10.50R1631.6
285/75R1633x12.50R1632.8
305/70R1633x12.50R1633.0

Conversion Chart by 17.5-Inch Wheels (chart, tire conversion, diameter)

P-MetricFlotationOutside Diameter (in)
235/75R17.531x10.50R17.531.0
245/70R17.532x10.50R17.532.0
265/70R17.533x11.50R17.533.0

Conversion Chart by 22.5-Inch Wheels (charts by wheel size, tire plus sizing, diameter)

P-MetricFlotationOutside Diameter (in)
275/80R22.539x13.50R22.539.6
295/75R22.540x14.00R22.540.0
315/80R22.542x14.00R22.542.0

Metric Conversion Tire Calculator: Cross-Referencing by Outside Diameter

15-Inch Outside Diameter Options (outside diameter, tire conversion chart, standard tire sizes)

P-MetricFlotation EquivalentOutside Diameter (in)
195/70R1424x8.00R1424.7
205/75R1425x8.00R1425.1
225/70R1426x8.50R1426.4

16-Inch Outside Diameter Options (diameter, tire size, conversion, charts by diameter)

P-MetricFlotation EquivalentOutside Diameter (in)
215/65R1627x8.00R1627.0
225/75R1629x9.50R1629.3
235/85R1632x9.50R1631.7

18-Inch Outside Diameter Options (tire conversion, compare tire sizes, overall diameter)

P-MetricFlotation EquivalentOutside Diameter (in)
265/60R1830x10.00R1830.5
285/60R1831x11.00R1831.5
305/60R1832x12.00R1832.6

20-Inch Outside Diameter Options (diameter, flotation size, inch and metric tire conversion)

P-MetricFlotation EquivalentOutside Diameter (in)
275/55R2031x11.00R2031.9
285/60R2033x11.50R2033.5
305/55R2033x12.50R2033.2

24-Inch Outside Diameter Options (diameter, tire conversion, charts by diameter)

P-MetricFlotation EquivalentOutside Diameter (in)
305/35R2434x12.50R2434.4
315/35R2435x12.50R2435.7
355/30R2436x15.00R2436.0
How Accurate Are These Conversions?

Values in these metric tire conversion chart use theoretical formulas, but always confirm with the manufacturer's specs or spec sheet for exact measured fitment details. Always account for small variations due to section height differences.

Tire Calculator Insights: Using a Calculator and Manual Conversion Steps

Using an Online Calculator (tire calculator, fastest way, easy to use)

  • Modern tire calculator tools are the fastest way to perform quick tire-related calculations between metric and flotation.
  • Just enter a measurement—metric or flotation—and get instant data, including calculated equivalent and the nearest standard measurement your local store or location may have in stock.
  • Great for 4x4 JK wheels, SUV, or off-pavement enthusiasts upgrading or swapping out gear.

Manual Conversion Steps (conversion, tire width, calculations, tire size)

Step-by-Step: Metric to Flotation
  1. Identify the metric size: For example, 285/75R16
  2. Calculate sidewall height:
    $$\text{Sidewall Height} = \text{Width} \times \frac{\text{Aspect Ratio}}{100}$$
    $$285 \times 0.75 = 213.75mm$$
    Section height is important for this calculation.
  3. Solve for overall measurement:
    $$\text{Total Height} = 2 \times \text{Sidewall Height} + \text{Wheel Diameter (in mm)}$$
    $$ 2 \times 213.75 + 406.4 = 833.9mm $$
    Then convert to inches: $$ 833.9 \div 25.4 = 32.8'' $$
  4. Convert width to inches: $$285mm \div 25.4 = 11.22''$$
  5. Flotation format: 33x11.50R16 (round diameter and width as necessary)
Step-by-Step: Flotation to Metric
  1. For a flotation size—e.g., 31x10.50R15—reverse the process:
  2. Overall dimension is given: 31"
  3. Tread width is given: 10.5" x 25.4 = 266.7mm
  4. Rim size: 15" x 25.4 = 381mm
  5. Sidewall Height:
    $$ (\text{Total Height} - \text{Wheel Size}) \div 2 = \text{Sidewall} $$
  6. Sidewall: (787.4mm - 381mm) / 2 = 203.2mm
  7. Aspect Ratio:
    $$ (\text{Sidewall Height} \div \text{Width}) \times 100 $$
  8. Aspect ratio: (203.2 / 266.7) x 100 = 76%
  9. Metric format: 265/75R15 (rounded nearest standard size)

Tire Plus Sizing and Fitment: Conversion and Compatibility Considerations

What is Plus Sizing? (tire plus sizing, plus sizing, rim upgrades, purchasing)

  • Plus sizing means increasing your wheel diameter (using larger wheels) while maintaining overall tire circumference to preserve speedometer accuracy and handling.
  • Allows for performance upgrades, enhanced aesthetics, and improved all-terrain or street capability for your vehicle.
  • Common among 4x4 TJ wheels, SUV, and crossover owners looking to optimize stance and traction.

Important Tire Fitment Considerations (tire fitment, tire compatibility, tire conversions, tire dimensions)

Check Before You Purchase
  • Ensure wheels and wheel assemblies are compatible with both new and existing options
  • Account for fender, suspension, and brake clearance—especially on lifted vehicles or all-terrain setups
  • Verify your choice with the brand’s published specs and fitment data
  • Keep diameter consistent when changing sizing for safety and performance

Real-World Examples: Metric Tire Conversion and Common Tire Replacements

Converting 265/75R16 to Flotation (tire conversion, 285/75r16, diameter, conversion examples)

  • Metric: 265/75R16
  • Overall: $$2 \times 265 \times 0.75 \div 25.4 + 16 = 31.6''$$
  • Closest flotation: 31x10.50R16
  • This tire match is popular for pickup and SUV upgrades

Translating 33x12.50R15 to Metric (tire conversion chart, tire conversion, compare tire sizes, diameter)

  • Flotation: 33x12.50R15
  • Tread width: 12.5" x 25.4 = 317.5mm
  • Overall: 33"
  • Find metric sizing with similar diameter: 315/75R15 (315mm, 75% aspect ratio, 15-inch rim)

Choosing Replacements: Metric vs Flotation (metric tire conversion, compare tire sizes, pickup)

Metric or Flotation for Your Application?

Flotation options are best for all-terrain, custom, and classic builds—easy to understand and often available in wider, taller options. Metric tire conversion results work best for passenger cars, crossovers, and modern SUVs. Always use a metric tire conversion chart to compare diameters and check for exact matches.

Tire Conversion Chart FAQ by Popular Diameters

15" Outside Diameter Tire FAQ (diameter, tire size)

What’s the closest metric equivalent to 31x10.50R15?
  • Metric: 265/75R15 (diameter and width are very similar; measures match within 0.2 inch)
  • Always confirm with brand-published fitment data before replacement

16" Outside Diameter Tire FAQ (diameter, metric tire sizes)

Is 285/75R16 really a 33-inch tire?
  • 285/75R16 has a total of approximately 32.8 inches—slightly less than a true 33”
  • Great flotation replacement: 33x12.50R16

18" Outside Diameter Tire FAQ (diameter, tire sizes)

What flotation tire is close to 275/65R18?
  • Metric 275/65R18 has a 32.1” diameter; flotation equivalent is roughly 32x11.50R18
  • Double check options using accurate published data from spec sheets

20" Outside Diameter Tire FAQ (diameter, tire plus sizing, wheels)

If I go up to 35x12.50R20, what’s the metric alternative?
  • 35x12.50R20 equals around 325/60R20 metric
  • Metric tire conversion and plus sizing help keep overall dimension within safe range for your wheel

24" Outside Diameter Tire FAQ (diameter, crossover, purchasing)

What do I need to know before upgrading to oversized 24-inch tires?
  • Review wheel, rim, and fender clearance – consult the brand’s published specs
  • Oversized rubber can affect crossover handling and require attention to engineering details

Flotation to Metric Tire Converter: Directional Comparison and Best Practices

Works In Both Directions: Metric to Flotation and Flotation to Metric Tire Converter

  • This service enables you to convert between flotation measurements and convert between metric options with equal ease.
  • Input any format to instantly show the equivalent and nearest standard sizing.
  • For your rig, right wheels, or adventure projects, the tool produces the key geometry and fitment info for precise results.
About Math vs Real-World Fit
  • Math-based methods use theoretical geometryactual numbers may vary up to 0.5 inch; always compare to manufacturer measurements and spec sheets.
  • A published spec or measured data from the brand should confirm your selection before making your purchase.

Chart References for Popular Builds: Metric Tire Conversion for Jeeps and Trucks

Jeep Wrangler Metric to Flotation Tire Sizes (jeep wrangler tires, jeep jk tires, jeep tj tires, jeep yj tires, diameter)

FlotationMetric EquivalentWheel Size
31x10.50R15265/75R1515"
33x12.50R15315/75R1515"
35x12.50R17315/70R1717"
37x12.50R20325/60R2020"

Truck & Off-Road Metric to Flotation Tire Equivalents (truck, off-road, diameter, tire sizes)

FlotationMetric EquivalentOverall Diameter (in)
31x10.50R15265/75R1531.6
33x12.50R17285/70R1732.7
35x12.50R20325/60R2035.4

Use this metric to flotation tire converter and metric tire conversion chart for any replacement or upgrade on your next 4x4 TJ wheels, SUV, or crossover build. Always confirm with the brand's published specs and actual measured info before buying to ensure the fit is right for your vehicle and parts, such as for jeep wrangler wheels, jeep jk wheels, jeep tj wheels, or jeep yj wheels.

How do I convert metric tire sizes to flotation format?

To convert metric to flotation, enter your metric tire dimensions (section width, aspect ratio, and rim diameter). The calculator will compute the equivalent flotation size showing overall diameter, section width, and rim diameter in inches. See also our calculate Tire Load Capacity.

What's the difference between metric and flotation tire sizing?

Metric sizing uses millimeters for width and percentage for aspect ratio (e.g., 235/75R15), while flotation sizing uses inches for overall diameter and width (e.g., 31x10.5R15). Flotation sizes are commonly used for off-road and truck tires.

How accurate are tire size conversions?

Conversions are mathematically accurate, but actual tire dimensions can vary by manufacturer and model by up to 3%. Always verify specifications with the tire manufacturer for critical applications.

What do the tire size numbers mean?

In metric sizing (235/75R15): 235 is section width in mm, 75 is aspect ratio (sidewall height as % of width), R indicates radial construction, and 15 is rim diameter in inches. In flotation (31x10.5R15): 31 is overall diameter, 10.5 is section width, and 15 is rim diameter, all in inches. You might also find our Wheel Size Calculator (Plus Sizing) useful.

Can I use converted tire sizes on my vehicle?

Converted sizes give you equivalent dimensions, but you should verify load rating, speed rating, and vehicle compatibility before purchasing. Consult your vehicle manual or tire professional for safety requirements.

Why would I want to convert between tire size formats?

Converting helps when shopping for tires, comparing sizes from different manufacturers, or when switching between metric and flotation tire types for off-road applications or specific vehicle requirements.

How do I calculate tire sidewall height?

For metric tires, sidewall height = (section width in mm × aspect ratio) ÷ 100. For flotation tires, sidewall height = (overall diameter - rim diameter) ÷ 2. The calculator performs these calculations automatically.

What affects tire revolutions per mile?

Tire revolutions per mile depend on the overall diameter - larger diameter tires complete fewer revolutions per mile. This affects speedometer accuracy and odometer readings when changing tire sizes.