TYRE CALCULATOR
Tyre Size 245/45R18 - Compatible Alternatives
Find compatible tyre sizes within your chosen rolling radius tolerance. Compare diameters, widths, and prices.
⭐ Popular Tyre Sizes
Click any size to see compatible alternatives
📐 How to Read Tyre Sizes
A tyre size like 225/45R18 breaks down as:
What is Rolling Radius?
Rolling radius is the distance from wheel centre to ground. Keeping within 2-3% of original ensures accurate speedometer, ABS, and gearbox function.
Find Cheaper Tyres
Alternative sizes are often significantly cheaper. Our calculator helps you find compatible options that won't compromise safety.
Performance Upgrades
Wider tyres = more grip. Narrower = better for winter. Our calculator shows rim width compatibility for safe upgrades.
❓ Frequently Asked Questions
2-3% is recommended for speedometer accuracy. 5% may be acceptable for some vehicles. Always consult a professional.
Yes, but check rim width compatibility. Our calculator shows approved rim width ranges for each tyre size.
Example: 2254518 = 225mm width, 45% aspect ratio, 18 inch rim. Use our calculator above to find compatible alternatives.
⚠️ Important: Always verify fitment with a professional tyre fitter. Maintaining rolling radius within 2-3% ensures accurate speedometer readings and safe vehicle operation.