Use this rubber grommet size chart to find the exact grommet for your panel hole. Grommets are sized by four dimensions — measure your panel hole diameter and panel thickness, then match them below.
How to Measure a Rubber Grommet
- Groove Diameter (fits panel hole) — the diameter of the recessed groove around the grommet. This must match your drilled hole size. It is the most important measurement.
- Groove Width (GW) — the width of the groove. This must match your panel or sheet metal thickness.
- Inside Diameter (ID) — the opening in the center that your wire, cable, hose, or tube passes through.
- Outside Diameter (OD) — the overall flange diameter. The OD must be larger than your hole so the grommet seats securely.
Quick rule: drill hole = groove diameter, panel thickness = groove width, and whatever passes through must be smaller than the ID.
Rubber Grommet Size Chart — Shop by Panel Hole Size
| Panel Hole (Groove Diameter) | Decimal (in.) | Shop Grommets |
|---|---|---|
| 1/4" | 0.250 | 1/4" Grommets |
| 5/16" | 0.313 | 5/16" Grommets |
| 3/8" | 0.375 | 3/8" Grommets |
| 7/16" | 0.438 | 7/16" Grommets |
| 1/2" | 0.500 | 1/2" Grommets |
| 9/16" | 0.563 | 9/16" Grommets |
| 5/8" | 0.625 | 5/8" Grommets |
| 3/4" | 0.750 | 3/4" Grommets |
| 7/8" | 0.875 | 7/8" Grommets |
| 1" | 1.000 | 1" Grommets |
| 1-1/16" | 1.063 | 1-1/16" Grommets |
| 1-1/4" | 1.250 | 1-1/4" Grommets |
| 1-3/8" | 1.375 | 1-3/8" Grommets |
| 1-1/2" | 1.500 | 1-1/2" Grommets |
| 1-5/8" | 1.625 | 1-5/8" Grommets |
| 1-3/4" | 1.750 | 1-3/4" Grommets |
| 2" | 2.000 | 2" Grommets |
| 2-1/4" | 2.250 | 2-1/4" Grommets |
| 2-7/16" | 2.438 | 2-7/16" Grommets |
| 2-1/2" | 2.500 | 2-1/2" Grommets |
| 2-3/4" | 2.750 | 2-3/4" Grommets |
| 2-7/8" | 2.875 | 2-7/8" Grommets |
| 3" | 3.000 | 3" Grommets |
| 3-1/4" | 3.250 | 3-1/4" Grommets |
| 3-1/2" | 3.500 | 3-1/2" Grommets |
| 3-3/4" | 3.750 | 3-3/4" Grommets |
| 4" | 4.000 | 4" Grommets |
| 4-3/16" | 4.188 | 4-3/16" Grommets |
Common Applications
Rubber grommets protect wires passing through sheet metal, seal electrical panel box knockouts, isolate vibration on compressors, and seal unused holes with blank/closed grommets. Browse the full rubber grommet collection.
Need a hole plugged instead of lined? See our rubber plugs and hole stoppers.