What is the Apple Watch connection distance to iPhone?

I had a question today, so I thought I’d research the answer and share it with you. I’m guessing that many people already wonder this and many more will wonder this as soon as Apple Watches begin shipping. The question is:

How far does the Wi-Fi/Bluetooth connection reach between the Apple Watch and iPhone?

This is an important question for many situations, including:

Using the Apple Watch at the gym for workouts and activity monitoring. Can the iPhone be in my bag in the corner, in my locker in the locker room, or does it have to be strapped to my upper arm or in my pocket?

Do I need to carry my iPhone on me at all times in the office and at home? What if my iPhone is in my bag, at my desk, or in my room?

The Apple Watch connects to the iPhone using Bluetooth 4.0. The Apple Watch does not have Wi-Fi, it uses the Wi-Fi in the iPhone, but don’t get too worried just yet. By itself, the Apple Watch can track fitness data, play music stored on the Watch, and make purchases using Apple Pay. Cool interaction goes on between the Apple Watch and the iPhone, for example: Handoffs. With Handoffs, you can start a message on the Apple Watch and then finish it on your iPhone.

The Apple Watch uses the Wi-Fi and GPS of your iPhone (iPhone 5 or later). But the watch does have an internal accelerometer and heart rate sensor. Does it not work without an iPhone? Well, it will work just fine, but certain apps won’t work without a paired iPhone.

Most apps will need a connected iPhone to work, as much of the processing for the apps is handled by the iPhone and then sends the result to Apple Watch via bluetooth. Apple does this to preserve the Apple Watch battery life.

So then if the iPhone connects to Wi-Fi and the Apple Watch connects to the iPhone via Bluetooth 4.0, the heart of this question is:

What is the range of Bluetooth 4.0?

Digging into this, I found that the distance of Bluetooth 4.0 can be up to 330 feet (100 meters) and sometimes more, BUT it can be much less, depending on many factors. Bluetooth uses radio waves (short-wavelength UHF to be exact) between 2.4 and 2.485 GHz in the ISM band. Long story short, that means that a Bluetooth signal can be interrupted by Wi-Fi signals, satellite dishes, certain external monitors, microwaves, bodies, certain electronics, etc.

So, how close do your Apple Watch and iPhone need to be in order for all of the Apple Watch features to work fully? Approximately 330 feet (100 meters) – more or less.

Take that into consideration when separating your Apple Watch from your iPhone.

Update: At the Apple event on 10 March, 2015 Kevin Lynch said: “Apple watch communicates with your iPhone over wifi as well as bluetooth. So when you’re home, you don’t have to be within bluetooth range of your phone, you can be anywhere in your house and still get all your messages and take your phone calls…”