What does 205/55R16 mean?
Decode 205/55R16: section width, aspect ratio, radial construction, rim inches, and approximate overall diameter for upgrade planning.
Decode 205/55R16
205 is nominal section width in millimeters. 55 is the aspect ratio: sidewall height is 55% of 205 mm (about 112.8 mm per side here). R means radial construction. 16 is rim diameter in inches.
Estimated overall diameter
Using the standard geometric model, overall diameter is roughly 631.9 mm. Compare this label to any candidate in the tire size calculator to see diameter and speedometer deltas before you buy.
Common misunderstandings
- The middle number is not sidewall millimeters—it is a percent of width.
- Rim inches are not the tire’s overall height.
- Printed sizes are nominal; molds vary slightly by brand.
Related resources
Read how to read tire size numbers or jump to the FAQ library for deeper articles.
Frequently asked questions
What is 55 in 205/55R16?
What rim fits 205/55R16?
How do I compare 205/55R16 to another tire?
Try the free tire size calculator
Open the interactive tire size calculator to compare diameters, see a wheel size comparison side by side, and review a speedometer difference table before you buy tires or wheels. It works like a quick tire fitment checker for geometry—not a substitute for a professional install bay.