Winter Tire Size Calculator

When switching to winter tires, going slightly narrower than your summer tires can dramatically improve grip on snow and ice — the Winter Tire Size Calculator works out the right size for your setup. Enter your current tire's width, aspect ratio, and rim diameter, then select your winter tire strategy (same size, minus one, or minus two) and primary concern to get your recommended winter tire size. Secondary outputs show the overall diameter change, width change, and new sidewall height so you can confirm fitment before you buy.

mm

Width of your current summer tire in millimeters

%

Sidewall height as percentage of width

in

Wheel diameter in inches

Narrower tires perform better in snow

Results

Recommended Winter Tire Size

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Overall Diameter Change

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Width Change

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New Sidewall Height

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Results Table

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Frequently Asked Questions

Why should I use narrower winter tires?

Narrower tires slice through snow more effectively than wide tires, which tend to 'float' on top. This improves traction and reduces the risk of getting stuck in snow.

What is minus sizing for winter tires?

Minus sizing means choosing a smaller wheel diameter with a higher sidewall tire. This provides better ride comfort, more air cushioning, and often lower cost while maintaining similar overall diameter.

How much can I change my tire size for winter?

Generally, you can safely vary the overall diameter by ±3%. Larger changes may affect speedometer accuracy, clearance, and vehicle performance.

Do I need to buy new wheels for winter tires?

Not necessarily. You can use the same wheels if you choose winter tires in the same size as your summer tires, though minus sizing often requires smaller diameter wheels.

Will winter tire sizing affect my speedometer?

Small diameter changes (within ±3%) have minimal impact. Our calculator shows the percentage difference to help you stay within safe limits.

Should I use four winter tires or just two?

Always use four matching winter tires. Using only two can create handling imbalances and reduce overall safety, especially in turns and during braking.

How do I read my current tire size?

Look on your tire sidewall for numbers like '225/60R17'. The first number is width (225mm), second is aspect ratio (60%), and the last is rim diameter (17 inches).

What's the best aspect ratio for winter tires?

Higher aspect ratios (60-70%) are generally better for winter driving as they provide more sidewall flexibility and comfort when driving over snow and ice.