How to Find Tire Size: Complete Guide 2025
Finding the right tire size for your vehicle is crucial for safety, performance, and fuel efficiency. Whether you're replacing worn tires or upgrading to new ones, knowing how to locate and understand tire size information will save you time and ensure you get the perfect fit.
Lead Automotive Technician
Decode tire size
Use the Tire Size Calculator to translate sidewall markings into exact dimensions.
Explore →Compare options
Stack two or more tire codes in the Tire Size Comparison tool to check diameter swings.
Explore →Confirm load & PSI
Feed the size into the Load Safety Validator and Tire Pressure Calculator for safe operation.
Explore →Where to Find Your Tire Size
1. On Your Current Tires (Sidewall)
The most reliable place to find your tire size is on the sidewall of your current tires. Look for a series of numbers and letters that typically appears in this format:
Example: P225/65R17 102H
This alphanumeric code contains all the information you need about your tire size. The marking is usually located on the outer sidewall and may appear in multiple locations around the tire.
2. Driver's Side Door Jamb
Open your driver's side door and look for a sticker or placard on the door frame. This manufacturer's label contains:
- Recommended tire size
- Proper tire pressure (PSI)
- Vehicle weight information
- Manufacturing date
3. Owner's Manual
Your vehicle's owner's manual contains the original equipment tire size specifications. This is particularly useful if:
- Your current tires are not the original size
- The sidewall markings are worn or damaged
- You want to verify the manufacturer's recommendations
Understanding Tire Size Numbers
Let's break down a typical tire size marking: P225/65R17 102H
P - Tire Type
- P: Passenger vehicle tire
- LT: Light truck tire
- ST: Special trailer tire
- T: Temporary spare tire
225 - Tire Width
- Measured in millimeters
- Width from sidewall to sidewall
- Wider tires provide better grip
Step-by-Step Guide
Step 1: Locate the Tire Markings
- Park your vehicle on level ground
- Examine the sidewall of any tire
- Look for the size marking (usually in white lettering)
- Clean the sidewall if markings are dirty or unclear
Step 2: Record the Complete Size
Write down the entire tire size code, including:
- All numbers and letters
- Any additional markings (DOT code, brand, model)
- Load index and speed rating
Tools to Help You
Online Tire Size Calculator
Use our free tire size calculator to:
- Convert between different size formats
- Compare tire dimensions
- Calculate speedometer differences
- Find equivalent sizes
Safety Considerations
- Never install tires smaller than manufacturer specifications
- Ensure adequate load capacity for your vehicle
- Match speed ratings to your driving needs
- Replace tires in sets when possible
Conclusion
Finding your tire size is a straightforward process once you know where to look and how to interpret the markings. Always prioritize safety by ensuring your replacement tires meet or exceed your vehicle manufacturer's specifications.
Use our tire size calculator to compare sizes, calculate differences, and ensure you're making the best choice for your vehicle and driving style.
Need help with tire size calculations? Try our free tire size calculator for instant results and comparisons.
Popular tire databases
Browse TireSize programmatic `/tiresize/[size]` pages for OE and upgrade references.
Learn more →Offset & clearance
Connect the decoded size to the Offset Visualizer to watch inner/outer movement.
Learn more →Speedometer check
After finding the code, run it through the Speedometer Correction calculator for MPH accuracy.
Learn more →How to find tire size FAQ
Where is the fastest place to find tire size information?+
Your driver-side door jamb placard lists the OEM size and PSI. Cross-check that data with the TireSize calculator to ensure your current tires match the placard or note any previous changes.
What if the sidewall markings are worn or unreadable?+
Reference the owner’s manual, VIN-specific service records, or the vehicle placard. You can also search the TireSize `/tiresize/[size]` directory to look up popular OEM codes for your trim.
Can I change tire size after finding the stock code?+
Yes, but keep total diameter within ±3%, maintain or exceed load index, and use the comparison + interference tools to confirm safe clearance before purchasing new tires.
Which tools help decode and validate tire sizes?+
Start with the tire size calculator to decode sidewall markings, then use tire size comparison, load safety validator, and speedometer correction pages to verify performance and safety impacts.
Do I need to adjust tire pressure after finding a new size?+
Always follow the placard PSI or manufacturer load tables. After finding the correct size, set cold PSI with the tire pressure calculator to ensure proper load carrying and TPMS compliance.
Disclaimer
The calculations and recommendations on this site are for informational purposes only. Always consult your vehicle manufacturer, tire professional, and local regulations before making any changes to tire or wheel size.