Tyre sizing notation for forklifts can be confusing — especially when the same tyre appears under multiple size names. This guide explains how to read and cross-reference solid tyre size markings.
The Three Common Forklift Tyre Size Formats
Forklift solid tyres are marked in three main systems, all referring to the same physical dimensions but expressed differently. This causes confusion when replacing tyres or cross-referencing between brands.
- Imperial inch format: e.g. 18×7-8 (overall diameter × section width — rim diameter, all in inches)
- Metric format: e.g. 180/70-8 (section width in mm / aspect ratio % — rim diameter in inches)
- Hybrid format: e.g. 8.15-15 (section width in inches — rim diameter in inches, no overall diameter)
Reading the Imperial Format: 18×7-8
This is the most common format used in Asian markets and the format used by most Chinese manufacturers. Breaking it down:
- 18 = overall tyre diameter in inches (the full outside diameter when mounted)
- 7 = section width in inches (the widest point of the tyre cross-section)
- 8 = rim diameter in inches (the wheel diameter the tyre mounts onto)
Reading the Metric Format: 180/70-8
The metric format is common on European and some American machines. Breaking it down:
- 180 = section width in millimetres
- 70 = aspect ratio — section height as a percentage of section width (180 × 70% = 126 mm section height)
- 8 = rim diameter in inches
Common Size Cross-References
The following pairs are direct equivalents — the same tyre sold under two different name conventions:
- 18×7-8 = 180/70-8
- 21×8-9 = 200/75-9
- 23×9-10 = 225/75-10
- 27×10-12 = 250/75-12
- 23×10-12 = 250/60-12
- 28×9-15 = 8.15-15 = 225/70-15
- 23×12-12 = 315/45-12
How to Find the Size on Your Existing Tyre
The tyre size is always moulded into the sidewall rubber. Look for a series of numbers on the flat face or angled sidewall. The size is typically followed by the word "SOLID" or "RESILIENT" and may include a load index and speed symbol.
If the sidewall is too worn to read, check the forklift's data plate (usually mounted near the operator seat or on the counterweight) which lists the tyre specification. Alternatively, measure the tyre: overall diameter, section width, and rim diameter — then cross-reference using the table above.
Have questions about your specific application?