How to Measure a Wheelchair Tire The Easy Way

Ever wondered why your wheelchair tire measurements seem different every time? Let's solve this mystery with a simple, foolproof method that anyone can do.

What You'll Need:

• Tape measure
• Something to write on
• Something to write with
• About 5 minutes of your time

The Simple Step-by-Step Process

1. Locate the rim of your wheelchair wheel (not the tire!)
2. Position your tape measure at the outermost edge of one side of the rim
3. Measure straight across the hub to the opposite outer edge of the rim
4. Important: Ensure you're measuring through the center of the wheel for accuracy
5. Write down the measurement
6. Compare your measurement to the chart below to determine your wheel's tire size.

Measurement Chart

Note: Not all rims have the same size side wall heights, so pick the closest one.

Note 2: These measurements apply to wheelchair wheels and tires only.

Why Measure the Rim and Not the Tire?

There are three important reasons why we focus on rim measurements:

1. Consistency: A flat tire measures differently than an inflated one (shocking, right?)
2. Tire Variety: Your wheel could have different tire sizes (1", 1-1/8", or 2") mounted on the same rim
3. Standardization: A 24" rim is always 24" - it's like the trustworthy friend who never changes

The Technical Deep Dive

For those who love the nitty-gritty details (we know you're out there!), let's get technical about why this measurement method works so well.

What we're actually measuring is the internal diameter of the rim - from the inside edge of one side to the inside edge of the other. Why? Because this is the crucial interface where tire meets rim.

Here's the fascinating part: If you had:

• A perfectly round tire
• A perfectly round rim
• And measured the inside diameter of both

The measurements would be identical in millimeters. This is the secret behind those mysterious tire size numbers you see!

Breaking Down the Numbers

Take a "24 x 1" tire for example:

• The metric equivalent is "25-540"
• 25 represents the tire width (25mm = 1 inch)
• 540 represents the internal rim diameter in millimeters

This standardized measurement system ensures that when you order a tire labeled "24 x 1" or "25-540", it will fit your 24-inch rim perfectly.

The Exception to the Rule

Warning: Wheelchair Humor Ahead

The only time this measurement method won't work is if your wheels are "pancaked" - where you wheel is not round because of damage. 😄

Quick Reference Guide

Remember these key points:

• Always measure the rim, not the tire
• Measure through the center of the wheel
• Double-check your measurements
• Use the metric system for most accurate results

Pro Tips for Success

1. Keep a record of your measurements for future reference
2. When in doubt, measure twice
3. Consider taking photos of your current setup before ordering
4. Remember that different tire types (sport, everyday, etc.) may have different sizing requirements

Need Help?

Still unsure about your measurements? Our team at Disability Lab is here to help! We've been measuring, fitting, and customizing wheelchair parts for years, and we're happy to assist.

Contact us