Calculadora de Tamaño de Neumáticos

Ingresa dos tamaños de neumáticos para comparar diámetro, circunferencia, ancho y error del velocímetro. Incluye visualización SVG lado a lado y tabla de equivalencias.

Tire Size

Width (mm)

Aspect Ratio (%)

Rim (inches)

Dimensions

Overall Diameter

634.3 mm

24.97"

Sidewall Height

101.3 mm

Circumference

1993 mm

Width (inches)

8.86"

Revolutions / km

502

Revolutions / mile

808

Section Height

101.3 mm

Rim Width

6" - 7" - 8"

Cross Section

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What is a Tire Size Calculator?

A Tire Size Calculator decodes tire size codes (such as 225/45R17) to reveal exact dimensions — overall diameter, sidewall height, circumference, and revolutions per kilometer. The first number (225) is the section width in millimeters, the second (45) is the aspect ratio (sidewall height as a percentage of width), R indicates radial construction, and the last number (17) is the rim diameter in inches. The calculator also compares two tire sizes to show speedometer error, ground clearance change, and whether the swap falls within the industry-standard 3% diameter tolerance. Plus-sizing (inch-up) mode automatically finds equivalent tire sizes when upgrading to larger rims, ensuring you maintain ride quality and safety.

How to Use the Tire Size Calculator

Select or enter your tire size using the width, aspect ratio, and rim diameter dropdowns
Use the Decoder tab to view full dimensions with an interactive SVG cross-section diagram
Switch to Comparison to compare two tire sizes — see speedometer correction and safety rating
Use Inch-Up to find compatible tire sizes when upgrading rim diameter (+1, +2, or +3 inches)
Use the Converter tab to switch between metric (225/45R17) and inch (25×8.9R17) tire formats

Frequently Asked Questions

What does 225/45R17 mean on a tire?

225 is the section width in millimeters (the tire's width from sidewall to sidewall when mounted). 45 is the aspect ratio — the sidewall height is 45% of the width (225 × 0.45 = 101.25 mm). R means radial construction (virtually all modern tires). 17 is the rim diameter in inches. Together, this tire has an overall diameter of approximately 634 mm (24.97 inches) and a circumference of about 1,993 mm.

How much tire size difference is safe?

The industry standard is a maximum 3% change in overall diameter from the original equipment tire. Within 1.5% is considered fully safe with negligible speedometer and odometer error. Between 1.5-3% requires caution — your speedometer will read slightly differently. Beyond 3% can affect ABS, traction control, transmission shift points, and may void manufacturer warranty. The calculator color-codes results: green (safe), yellow (caution), and red (danger).

What is plus sizing or inch-up?

Plus sizing (called '인치업' in Korean) is upgrading to a larger rim diameter while selecting a tire with a lower aspect ratio to maintain approximately the same overall diameter. For example, going from 205/55R16 to 225/45R17 (+1 inch rim) keeps the overall diameter within 1%. Benefits include improved handling and aesthetics. The trade-off is a stiffer ride and potentially higher cost. The Plus Sizing tab automatically calculates compatible options within the 3% safety tolerance.

How does tire size affect speedometer accuracy?

A larger tire covers more ground per revolution, so your speedometer will read lower than your actual speed. For example, if you increase overall diameter by 3%, when your speedometer shows 100 km/h, you're actually traveling at 103 km/h. Conversely, smaller tires make the speedometer read higher than actual speed. The calculator shows the exact speedometer correction and odometer drift per 1,000 km for any tire size change.