How to Read Forklift Tyre Sizes
Forklift tyres use two different size formats. Here is exactly what each number means, with a full reference table of common solid cushion tyre sizes.
Two Formats, One Logic
Solid forklift tyre sizes use two common designation formats. Both describe the same three dimensions: outer diameter, tyre width, and rim diameter — all in inches.
Format 1: Width × Rim (e.g. 6.00 x 9)
This is the older, shorter format. It gives you two numbers:
| Position | What it means | Example: 6.00 x 9 |
|---|---|---|
| First number | Section width of the tyre in inches | 6.00 inches wide |
| Second number (after ×) | Rim diameter in inches | Fits a 9-inch rim |
The outer diameter is not stated in this format — it is determined by the tyre construction. For a 6.00×9 solid cushion tyre, the standard outer diameter is 21 inches.
Common Width × Rim sizes: 4.00×8, 5.00×8, 6.00×9, 6.50×10, 7.00×12, 7.50×15, 8.15×15, 8.25×15, 8.25×16, 9.00×20, 10.00×20
Format 2: OD × Width-Rim (e.g. 18 x 7-8)
This format is more descriptive — it gives all three dimensions explicitly:
| Position | What it means | Example: 18 x 7-8 |
|---|---|---|
| First number | Outer diameter of the tyre in inches | 18 inches OD |
| Second number (after ×) | Nominal width of the tyre in inches | 7 inches wide (nominal) |
| Third number (after –) | Rim diameter in inches | Fits an 8-inch rim |
Common OD × Width-Rim sizes: 15×4.5-8, 16×6-8, 18×7-8, 21×8-9, 23×9-10, 27×10-12, 28×9-15, 250×15, 300×15
Are Two Sizes the Same Tyre?
Sometimes yes. Many solid tyre sizes have equivalent designations in both formats. The most common example:
| Width × Rim Format | OD × Width-Rim Format | Outer Diameter | Rim Size |
|---|---|---|---|
| 8.15 × 15 | 28 × 9-15 | 28 in | 15 in |
| 6.50 × 10 | 23 × 9-10 (approx.) | 23 in | 10 in |
| 6.00 × 9 | 21 × 8-9 (approx.) | 21 in | 9 in |
When in doubt, always cross-check using your forklift OEM data plate or the size moulded on the sidewall of your existing tyre. The rim diameter is the most critical dimension — it must match exactly.
Full Size Reference Table
All solid resilient sizes manufactured by Adamas, with key specifications:
| Size | Outer Dia. | Width | Rim | Drive Capacity |
|---|---|---|---|---|
| 4.00 × 8 | 16 in | 4.0 in | 3 in | 930 kg |
| 15 × 4.5-8 | 15 in | 4.5 in | 3 in | 1,040 kg |
| 5.00 × 8 | 18 in | 5.0 in | 3 in | 1,390 kg |
| 16 × 6-8 | 16 in | 6.0 in | 4.33 in | 1,270 kg |
| 18 × 7-8 | 18 in | 6.0 in | 4.33 in | 2,000 kg |
| 6.00 × 9 | 21 in | 6.0 in | 4 in | 1,840 kg |
| 21 × 8-9 | 21 in | 8.0 in | 6 in | 2,800 kg |
| 6.50 × 10 | 23 in | 6.5 in | 5/5.5 in | 2,310 kg |
| 23 × 9-10 | 23 in | 8.15 in | 6.5 in | 3,420 kg |
| 7.00 × 12 | 26 in | 7.0 in | 5 in | 2,920 kg |
| 27 × 10-12 | 27 in | 10 in | 8 in | 3,450 kg |
| 8.15 × 15 (28×9-15) | 28 in | 9.0 in | 7 in | 3,450 kg |
| 250 × 15 | 28 in | 9.0 in | 7 in | 4,600 kg |
| 8.25 × 15 | 32 in | 8.3 in | 6.5 in | 4,960 kg |
| 300 × 15 | 32 in | 10 in | 8 in | 5,725 kg |
| 7.50 × 16 | 29 in | 7.4 in | 6 in | 3,880 kg |
| 8.25 × 16 | 32 in | 8.3 in | 6 in | 3,900 kg |
| 7.50 × 20 | 34.5 in | 7.7 in | 6 in | 4,200 kg |
| 9.00 × 20 | 39 in | 9.2 in | 6.5/7 in | 5,375 kg |
| 10.00 × 20 | 40 in | 10 in | 7/7.5/8 in | 6,000 kg |
How to Find the Right Size for Your Forklift
- Check the data plate — mounted on the mast or side panel of your forklift. Lists the approved tyre size.
- Read the tyre sidewall — the size is moulded into the rubber on the outer sidewall.
- Check the OEM manual — your forklift service manual lists tyre specifications by model.
- Contact us — share your forklift make, model, and year and we will confirm the correct size.
Size-Specific Pages
We have detailed specification and quote pages for these sizes: