What's the maximum file transfer speed over WiFi 802.11g?

Unless the computers are connected by an ad-hoc wireless network, it is the distance between the computer and the access point that is important.

54 Mbps is a theoretical throughput, which is roughly equivalent to 6,75MB/s. So you can expect up to 6,75MB/s as network bandwidth.

But when you are transferring files, the bandwidth is not fully used for transfer because of:

• Wireless control frames
• Network overhead (IP headers)
• File Transfer Protocol overhead
• Packet loss
• Interference and retransmission

At the end, the best you can expect is around 4MB/s in real transfer rate with a light protocol (like HTTP).

Mb/s means megabits per second. To convert to megabytes, you simply divide by 8, since there are 8 bits in a byte.

So 54Mb/s = 54Mb/s * 1Mb/8MB = 6.75MB/s

So you can theoretically cap out at just under 7 megabytes per second on 802.11g. :)

This source is very handy in comparing the various throughput's of different networking media. As they note, depending on the technology there can be a large difference between the stated raw physical layer speed, and the actual payload throughput.

For 802.11g they list a maximum throughput of 3.1 MB/s

Also, note that 802.11g connections can actually get worse if you place the peers too close to each other. Not all manuals list this, but try keeping both machine at least 20 centimeters apart.