How many kilometres or metres can typical phones communicate with each other? I mean, two phones.

The maximum direct communication distance between two typical smartphones varies wildly depending on your environment, but in everyday scenarios, it falls within 10 to 100 metres. [1] Because phones utilize standard consumer-grade internal antennas, the real-world communication breakdown plays out across distinct thresholds: [2, 3]

Real-World Distance Thresholds

0m 10m 30m 100m

|-------------------------|-----------------------|-----------------------------------------|

[ Indoor Stable Range ]
Walls, furniture, bodies. [ Outdoor Urban ] (5m – 10m) Signals crowded by cars, [ Open-Field / Direct Line-of-Sight ] trees, and structures. No physical obstacles, flat terrain, (15m – 30m) low wireless interference. (70m – 100m)

Indoors (5 to 10 metres): This is the typical stable limit inside a home or office. Drywall, furniture, and especially the water content in human bodies absorb the 2.4 GHz radio frequency. Concrete or brick walls can drop this down to just 2 to 3 metres. [1, 4, 5]
Outdoor Urban Spaces (15 to 30 metres): In a crowded street or park, you will reliably get a bit more distance because there are fewer thick walls. However, cars, trees, and heavy background Wi-Fi interference from nearby buildings will still degrade the signal past 30 metres. [4]
Open Field / Line-of-Sight (70 to 100 metres): If you and a friend are standing in an empty field, a desert, or on a long, flat beach with zero obstructions between your phones, standard Bluetooth Low Energy (BLE) can stretch up to 100 metres before dropping the packet completely. [6, 7, 8]

What prevents phones from going further?

While industrial Bluetooth beacons can broadcast up to 1 kilometer using specialized, high-power external antennas, smartphones are constrained by deliberate design choices: [8, 9, 10]

Strict Battery Optimization: Mobile operating systems intentionally restrict the Transmission Power (Tx Power) of the Bluetooth chip. If a phone broadcasted at maximum hardware capability all the time to reach farther, your battery would drain in hours. [2, 11]
Tiny Internal Antennas: Phone manufacturers must pack Bluetooth, Wi-Fi, 5G, and NFC antennas into a razor-thin chassis. These tiny, omnidirectional antennas are not optimized for long-distance beamforming.
The 2.4 GHz Crowd: Bluetooth operates on the exact same frequency band as your home Wi-Fi network, microwave ovens, and baby monitors. In any populated area, "wireless noise" naturally limits how far a tiny phone signal can travel before being drowned out. [1, 4, 12]

Note: This specific 30-to-100 metre hardware limit between two individual phones is exactly why apps like BitChat rely on mesh networking. By using intermediate phones as stepping stones every 30 metres, the data can travel kilometers across a crowd, even though no single phone signal can shoot that far on its own. Are you trying to figure out if two phones can connect across a specific environment (like between two apartments or across a football stadium), or are you looking to understand how to optimize your phone settings to get the maximum possible distance?

[1] https://consumer.huawei.com [2] https://www.bose.com [3] https://www.adorama.com [4] https://shokz.com [5] https://www.pointr.tech [6] https://en.wikipedia.org [7] https://elainnovation.com [8] https://www.cdebyte.com [9] https://www.blueiot.com [10] https://www.quora.com [11] https://stackoverflow.com [12] https://novelbits.io