For 12 AWG single wire, conductor area is about 3.31 mm².
Wire Ferrule Size Converter
Convert AWG or metric conductor size into a practical ferrule size in mm². Check single ferrules, twin ferrules for two matching wires, and common ferrule color-code notes.
Find the ferrule size
Enter the wire size, choose single or twin ferrule, and compare the conductor area with common insulated ferrule sizes.
Next smaller2.5 mm²
Typical DIN colorOrange
Fit noteCheck crimper die and terminal opening
12 AWG is larger than 2.5 mm² and closest to a 4.0 mm² ferrule size.
How to use the ferrule converter
- Enter the wire gauge, conductor area, or bare conductor diameter.
- Choose single ferrule for one wire or twin ferrule for two same-size wires in one ferrule.
- Use the recommended mm² ferrule as a starting point.
- Confirm the ferrule fits your terminal block, crimper die, and manufacturer wire range.
Why ferrule sizing is not only color matching
Ferrules are normally sold by conductor cross-section, such as 0.75 mm², 1.5 mm², or 2.5 mm². AWG wire sizes do not always land exactly on those metric sizes, so the next larger common ferrule is often the practical match.
Color helps when sorting parts, but ferrule color codes are not universal. The printed size and datasheet matter more than the plastic collar color.
Common ferrule size chart
Use this table as a quick reference for common ferrule sizes, approximate AWG matches, and typical DIN-style collar colors. Manufacturer charts may vary.
| Ferrule size | Approx. AWG range | Typical DIN color | Notes |
|---|
Wire ferrule size FAQ
Should the ferrule be exactly the same mm² as the wire?
Use a ferrule rated for the conductor cross-section. If your converted AWG area is between common metric ferrule sizes, the next larger size is usually the first one to test, but it must still crimp tightly and fit the terminal.
How do twin ferrules work?
A twin ferrule is sized for the combined area of two conductors. Two 1.5 mm² wires need a twin ferrule intended for about 3.0 mm² combined conductor area, often sold as a twin 1.5 mm² ferrule.
Can I use this for solid wire?
Ferrules are mainly used on finely stranded conductors. Some terminals and ferrules may allow other wire constructions, but you should follow the terminal and ferrule manufacturer specifications.