The USB cable is one of the most commonly used cables in the electronics world. 

They are used to connect computers to peripheral devices which include, printers, mobile phones, cameras, webcams and many more. 

Their main purpose is to provide means to transfer data from one device to another. They have the capabilities of charging mobile devices. 

USB cables come in a variety of different lengths.

But, how long should a USB cable be? How long a USB cable should be depends on the application it will be used for. The main factor in choosing how long it will be is the distance between devices that the USB cable will be used to transfer data or charging purposes. They range in lengths from 30cm (1ft) to 5m (16ft 5in).

What are the different types of USB cables?

Let’s take a look at the different types of USB cables which will give us a better picture at how long they should be for different applications. 

The main purpose of a USB cable is to transfer data from one device to another. The main device is usually a computer which is in control of transferring or receiving information from a peripheral device.

A USB cable is also capable of charging mobile devices that have rechargeable batteries. 

Below are the different types of USB cable available (the type of cable is the plug at the end of the cable on one side or both. A USB cable can also be a combination of two different types of cable at either end):

  • USB-A – The USB-A is most commonly connected to computer USB ports, and power outlets (that have the same USB input ports as computers). They can only be plugged in one way.
  • USB-B – This type of cable is usually used to connect printers, external hard drives, scanners, etc, to a computer
  • Mini-USB – these cables are most associated with mobile devices, Digital Cameras, MP3 players. They are used to transfer data to and from these devices, and have the ability to charge them too 
  • Micro-USB – the Micro-USB is most commonly used with Smartphones. It is used for data transfer and recharging purposes. 
  • USB-C – This cable is slowly replacing the Micro-USB. It serves the same functionalities, however, provides faster data transfers, and can be plugged in either way round.

Another note to add is, USB cable plugs have genders (yep, you read that right). They can be Male-Male, Female-Male, and Female-Female. 

Picking what gender of plug to use depends on the application it will be used for.

What are the different lengths of USB cable available?

Before you decide how long a USB cable you require, you will need to know what lengths are available. 

Then you can accordingly choose a USB cable that suits your needs.

There are a variety of lengths available, which can be as small as 30cm (1 foot), all the way up to 5m (16 feet, 5 inches).

However, when using USB 3.0 versions of a cable, the maximum length of a USB cable should not exceed 3m (9 feet, 10 inches).

For USB 2.0 cables, the maximum length of a USB cable should not exceed 5m (16 feet, 5 inches).

Factors that will determine how long a USB cable should be?

Now that you are familiar with the different types of USB cables, and the lengths available, let’s take a look at what will determine how long the USB cable should be. 

The biggest factor that is going to affect how long a USB cable you are going to need is the distance between the devices you are going to be connecting.  

The best way to pick the right size for a USB cable is to use a measuring tape and measure the distance between two devices and get a cable that is a little longer (to be on the safe side).

If the distance from one device to another is 1m (3 feet, 2 inches), it’s best to get a USB cable that is 1.5m (4 feet, 9 inches) long. 

Devices that determine how a long USB cable should be

So, distance is one of the biggest factors that will determine how long USB should be. The devices being used and their physical setup (placement of devices) will also play a part in choosing the right USB length. 

Distance however, will still be playing a role in the physical setup as well. 

Below are some of the most common devices that use USB ports and therefore require a USB cable :

  • Desktop Computers 
  • Desktop Computer Peripherals (keyboards, mouse, printer, webcam, scanner etc)
  • Mobile Devices (Smartphones, Digital Cameras, MP3 players etc)
  • Entertainment Systems (Smart TV’s, Gaming Consoles, DVD players etc)

There are many electronic devices that require USB cables, but the ones mentioned above are just some of the most common.

When you are connecting external peripherals (printers, scanners, webcams, etc) to a desktop computer, you will need USB cables that are longer in length (around 1.5 – 2m / 4ft inches – 6ft 5inches). Since, these devices will be placed away from computer’s USB ports.

The same goes for an entertainment system which can include devices such as a Smart TV, DVD player, gaming console, speakers etc. All the devices will be placed away in different locations and will require longer USB cables. Again, measuring the distance will allow you know exactly how long it has to be.

Since mobile devices are not fixed to a certain place and can be moved around, the length of the USB cable required for them depends on your needs. 

If you are transferring files to your laptop, or desktop PC , the cable does not have to be that long.

If you are like me and charge your phone overnight and use the phone while in bed, you might require a longer cable as the power outlet might not be located near your bed. 

So, depending on how you use your mobile devices will ultimately be the factor on the length of USB cable you will need. 

Can you make a short USB cable long?

A 5m (16ft 5 in) USB cable is of the longest available for USB 2.0 and 3m (9ft 10in) for USB 3.0. But, what if you need to extend it and make it longer.

There are instances where you might be setting up devices that are in different rooms which are greater than the length of the USB cable. 

The good news is that you can extend USB cables using  these methods below:

USB Hubs

This is essentially a device that expands a single Universal Serial Bus port into several more. The device you are using might only have one USB port or, you might have run out USB ports, so the USB hub can provide more inputs.

Active (Repeater) Extension Cables

The Active (repeater) extension cable provides a means of extending normal USB cables. It has the ability to regenerate the USB signal from your standard USB cable. 

Think of it as a 1 port USB hub. 

Using a combination of a USB hub and Active (repeater) extension cable, you can extend your standard USB cable. 

Can how long a USB cable is affect data transfer speed?

If you are using USB cables of longer length that are within their specifications (5m for USB 2.0 and 3m for USB 3.0), it will not affect the data transfer speeds.

However, if you are extending a USB cable considerably, say 100m, this might reduce data transfer speeds. But, this is technically not a standard USB cable, as you have modified its length. 

Another note to make is the quality of the USB cable. If it is poorly manufactured and constructed, you will have performance issues that could affect data transfer speeds. 

Problems with longer USB cables

One of the biggest problems with longer USB cables is managing them.

They can get messy when setting up entertainment and computer systems (any system that requires many long USB cables).

They can coil, and bend in directions that you do not want them to.

How to manage longer USB cables

Below is a great video on how to manage a variety of different cables.