DC Barrel Connector Sizing Chart
DC power plugs are identified by millimeter dimensions: Outer Diameter (OD) × Inner Pin Diameter (ID).
DC Barrel Connector Anatomy
Why 5.5×2.1 mm and 5.5×2.5 mm look identical but are not interchangeable
Narrow 2.1 mm center pin. Common on routers, switches, LED lights, and desktop monitors.
Wider 2.5 mm center pin. Common on high-power laptops, audio gear, and 60W+ power bricks.
Interactive DC Barrel Connector Finder
Search 15+ plug sizes by millimeter caliper measurements or device brand names.
Standard DC Barrel Dimensions
Millimeter Specs| Connector Type | Outer Diam. (OD) | Center Pin (ID) | Common Device Categories |
|---|---|---|---|
| 5.5 × 2.1 mm (Most Common DC) | 5.5 mm | 2.1 mm | Routers, LED strips, CCTV, monitors, external drives |
| 5.5 × 2.5 mm (High Current DC) | 5.5 mm | 2.5 mm | Laptops, high-power routers, audio amplifiers |
| 3.5 × 1.35 mm (Compact DC) | 3.5 mm | 1.35 mm | USB hubs, small desk fans, IP cameras, TV boxes |
| 4.0 × 1.7 mm (Small Electronics) | 4.0 mm | 1.7 mm | Older Sony/Asus gadgets, portable DVD players |
| 4.8 × 1.7 mm (Yellow Tip / Bullet) | 4.8 mm | 1.7 mm | HP Compaq laptops, older electronics |
| 3.0 × 1.1 mm (Micro DC) | 3.0 mm | 1.1 mm | Ultrabooks, Acer tablets, slim devices |
| USB-C (Power Delivery) | N/A | N/A | Modern laptops, phones, smart devices (requires PD negotiation) |
| Other Barrel Connector | Custom | Custom | Specialized or proprietary plugs |
| I don't know the connector size | Unknown | Unknown | Check device manual or measure with caliper |
How to Measure with a Digital Caliper
- Outer Diameter (OD): Close the outer caliper jaws around the metal cylinder of the male plug. Common values are 5.5mm, 3.5mm, 4.0mm.
- Inner Diameter (ID): Use the internal caliper points inside the hollow center of the male plug. Common values are 2.1mm or 2.5mm.
- Barrel Length: Standard barrel length across consumer electronics is 9.5mm to 10mm.
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Verify that your replacement power plug matches your device socket before plugging it in.
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