Headphone Jack Size report
Headphones accept electrical signals from media players and convert them into audible sound waves. The headphones can be detached from the media player and connected with one plug, allowing people to listen to music alone without disturbing others.
Headphones were originally used on telephones and radios. Still, with the prevalence of portable electronic devices, headphones are mostly used in mobile phones, walkmans, radios, portable video games, and digital audio players.
From the perspective of the development of the entire audio industry, the popularity of wireless earphones is on the rise, user demand is constantly increasing, and users' expectations for wireless earphones are also increasing, which is undoubtedly a challenge for the wired earphone industry. The following post introduces different headphone jack sizes you should know before buying a new wired earphone.
Headphone Jack Size Guide
The history of the headphone jack has been almost as long as that of the telephone. Its original use was on switches in the 19th century, when operators needed to wire them manually. They needed a way to make and break the electrical connections that carry audio easily, so the original phone jack was born.
Telephone jacks come in a variety of sizes. The jacks in the 19th century were 1/4 inch (6.35mm), but the most common ones are 3.5mm headphone jacks today. The first-generation Sony Walkman was a huge hit with headphones with a 3.5mm jack, and it revolutionized the world of portable audio. The 2.5mm headphone jack was popular in the 2000s and was commonly used in Nokia phones. But as larger-sized jacks are more popular in home electronics, 3.5mm won out in the end.
Headphone Jack Size Chart
You should be aware of a few different headphone jack sizes when using wired headphones. Size is the primary difference between 2.5mm, 3.5mm, and 6.35mm headphone jacks. The numbers refer to the diameter of the jack, but the lengths of the connectors are also different. Specific applications require certain standard sizes.
| Plug Diameter(inch) | lug Diameter(mm) | Plug Length(inch) | Plug Length(mm) |
|---|---|---|---|
| - | 2.5mm | 0.43" | 11mm |
| 1/8" | 3.5mm | 0.55" - 0.69" | 14mm - 17mm |
| 1/4" | 6.35mm | 1.18" - 1.22" | 30mm - 31mm |
- 3.5mm (1/8 inch)
3.5mm jacks are found on most portable CD players, MP3 players, and boom boxes, and also the headphone jacks used by most computer speakers and on computer sound cards for line in, line out, and microphone connections.
- 2.5mm
2.5mm headphone jacks are commonly used on mobile phones, two-way radios, and small electronic devices.
- 6.35mm (1/4 inch)
Stereo 6.35mm headphone jacks are usually referred to as 1/4 inch and are commonly used for the plugs on home stereo equipment. Mono 6.35mm jacks are used on electric guitars, amplifiers, and other music equipment.
Conclusion
New challenges are also coming. The increasingly popular Type C port gradually replaces the 3.5mm headphone jack, at least on smartphones. Interestingly, an official way is to connect the USB-C pins to the TRRS jack, which allows for a cheap, simple 3.5mm adapter without sacrificing audio quality. For example, the Huawei P20 Pro comes with USB-C headphones, using digital audio and its DAC, and an analog audio USB-C to 3.5mm converter. However, there is no doubt that the 3.5mm headphone jack is still the most popular, and this model is compatible with almost most mobile phones.
