The 2.4 GHz Wi-Fi displays theoretical speeds that vary significantly depending on the standard used. Between the early 802.11b devices and the current Wi-Fi 6 routers, the speed ceiling has been multiplied by a significant factor, yet this band has not become a rival to the 5 GHz band. Understanding where the real bottleneck lies helps to calibrate expectations and choose the right settings.
Theoretical speeds of 2.4 GHz Wi-Fi by standard: comparison table
The maximum announced speed for the 2.4 GHz band directly depends on the IEEE 802.11 standard supported by the router and the connected device. Here are the values documented by manufacturers and standardization bodies.
| Wi-Fi Standard | Year | Max Theoretical Speed (2.4 GHz) | Typical Channel Width |
|---|---|---|---|
| 802.11b | 1999 | 11 Mbit/s | 20 MHz |
| 802.11g | 2003 | 54 Mbit/s | 20 MHz |
| 802.11n (Wi-Fi 4) | 2009 | 300 Mbit/s (2 MIMO streams, 40 MHz channel) | 20 or 40 MHz |
| 802.11ax (Wi-Fi 6) | 2020 | Up to about 600 Mbit/s (optimized conditions) | 20 or 40 MHz |
| 802.11be (Wi-Fi 7) | 2024+ | About 346 Mbit/s (measured on certain HPE access points) | 20 MHz |
The figure for Wi-Fi 7 at 2.4 GHz is surprising. One might expect a leap comparable to that observed in 5 or 6 GHz, but the 2.4 GHz band remains constrained by its limited spectral width. The gains of Wi-Fi 7 are concentrated on the higher bands, not on this frequency.
To better situate the maximum speed of 2.4 GHz Wi-Fi in daily use, it is important to keep in mind that the actual throughput systematically drops compared to these theoretical maximums.
Why the actual speed of 2.4 GHz Wi-Fi remains well below the theoretical maximum
The figures in the previous table correspond to laboratory conditions: a single device, no competing networks, minimal distance. In real situations, several mechanisms drastically reduce speed.
Non-overlapping channels and contention between networks
Only three channels are truly non-overlapping in 2.4 GHz: channels 1, 6, and 11 (at 20 MHz width). In a building, each apartment broadcasts its own network on one of these three channels. The router must then share antenna time with neighboring networks, which reduces the available throughput for each user.
This contention is the primary cause of slowdowns in 2.4 GHz. It has nothing to do with the quality of the router or the box: it is a physical constraint related to the available spectrum.
Non-Wi-Fi Interference
The 2.4 GHz band is shared with technologies that have nothing to do with the internet network:
- Microwave ovens emit in this frequency range and can saturate the signal during operation
- Bluetooth also uses the 2.4 GHz band, with a frequency-hopping mechanism that generates micro-interruptions
- Some smart home devices (Zigbee, wireless remote controls) occupy portions of this spectrum
These sources of interference degrade the signal-to-noise ratio and force the router to retransmit packets, which divides the effective throughput.
Wi-Fi 6 at 2.4 GHz: collective efficiency rather than raw speed
Wi-Fi 6 (802.11ax) introduced two technologies that change the behavior of the 2.4 GHz band without necessarily increasing the speed of an isolated transfer.
OFDMA allows a channel to be divided into sub-channels assigned simultaneously to multiple devices. A smart home sensor sending a few bytes of data no longer monopolizes the entire channel during its transmission. The gain is mainly measured when a dozen connected objects share the same network.
BSS Coloring, on the other hand, allows the router to distinguish frames coming from neighboring networks and transmit in parallel when the channel is occupied by a foreign network. In a dense environment, the gain in collective capacity can reach a significant level while the peak throughput for a single device remains similar to Wi-Fi 5.
This distinction between maximum throughput and collective capacity is often absent from product specifications. A Wi-Fi 6 router will not dramatically speed up the download of a large file on the 2.4 GHz band. However, it will maintain a more stable network when multiple devices are transmitting at the same time.
20 MHz or 40 MHz channel width in 2.4 GHz: a false performance lever
With Wi-Fi 4, the ability to switch to a 40 MHz channel in 2.4 GHz doubled the theoretical throughput. On paper, it’s tempting. In practice, using a 40 MHz channel occupies two of the three non-overlapping channels available.
A 40 MHz channel in 2.4 GHz harms overall performance as soon as a neighboring network is present. The router picks up more interference, retransmits more packets, and often ends up automatically switching to 20 MHz. Most operator boxes in France (Orange, Free, SFR, Bouygues Telecom) actually force the width to 20 MHz by default on this band.
This setting is relevant. It is better to have a stable 20 MHz channel than a constantly disrupted 40 MHz channel. The actual throughput will be more consistent and latency more predictable, which matters for connected devices and video calls.
When the 2.4 GHz band remains the right choice despite its limited speed
The superior range of the 2.4 GHz signal compared to 5 GHz gives it a clear advantage in certain configurations. Lower frequency waves penetrate walls and floors better, which maintains a usable connection at greater distances from the router.
- Smart home devices (thermostats, sensors, smart plugs) that transmit low volumes of data perform better on 2.4 GHz due to the stability of the coverage
- Devices located two rooms or one floor away from the router often receive a 2.4 GHz signal that is sufficient where 5 GHz does not reach
- Older equipment that only supports Wi-Fi 4 has access only to this band and remains operational for web browsing or audio streaming
The 2.4 GHz band is not obsolete, but its role has changed. It serves as a coverage net for low-bandwidth devices and areas far from the router. Reserving 5 GHz (or 6 GHz) for bandwidth-intensive uses remains the most effective configuration on a modern box.
