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Wi-Fi throughput calculator.

Choose the Wi-Fi generation, channel width, spatial streams and MCS to get the theoretical link rate, then a rough real-world figure.

Wi-Fi 4, 5, 620 to 160 MHzMCS and streams

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Inputs

802.11n supports 20 and 40 MHz only.
Whole number, 1 to 4 for 802.11n and up to 8 for ac and ax.
Highest: 7 (n), 9 (ac), 11 (ax). A weaker signal uses a lower MCS.
Short for n/ac, microseconds for ax. Shortest is the best case.
A rough rule of thumb of overheads, contention and retries. It is an assumption, not a published figure.

Result

Enter your numbers.

Wi-Fi Throughput Calculator: how it works

The OFDM link rate is: data subcarriers x bits per subcarrier for the modulation x coding rate x spatial streams, divided by the symbol time. Data subcarriers depend on channel width: 52, 108, 234 and 468 for 20, 40, 80 and 160 MHz in 802.11n/ac, and 234, 468, 980 and 1,960 in 802.11ax. The symbol time is 3.6 us (short guard interval) or 4.0 us in n/ac and 12.8 us plus the guard interval in ax. The MCS sets modulation and coding rate, for example MCS 9 is 256-QAM 5/6 and MCS 11 in ax is 1024-QAM 5/6.

The results reproduce the data-rate tables in Wikipedia's 802.11n, 802.11ac and Wi-Fi 6 articles: 433.3 Mbps for 802.11ac, 80 MHz, 1 stream, MCS 9, short GI; 600.5 Mbps for 802.11ax, 80 MHz, 1 stream, MCS 11, 0.8 us.

Worked example. 802.11ax, 80 MHz, 2 streams, MCS 11, 0.8 us: 980 x 10 bits x 5/6 x 2 / 13.6 us = 1,201 Mbps. At 60% real-world share, about 721 Mbps. The link rate is shared by the devices using the channel, so a single device seldom sees the full number.

Frequently asked questions

What is the maximum speed of 80 MHz Wi-Fi 6?

Per stream it is 600.5 Mbps at MCS 11 with a 0.8 us guard interval, per Wikipedia's table. Two streams gives 1,201 Mbps.

Why is real Wi-Fi speed lower than the link rate?

Overheads, other devices sharing the channel, retries, distance and interference. This tool applies a share you choose; 60% is an assumption.

What is MCS?

The modulation and coding scheme index. Higher MCS packs more bits per symbol and needs a stronger, cleaner signal.

Does a wider channel always help?

It raises the top rate, but real results also depend on signal quality and interference, so wider is not always faster in practice.

Sources

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Not professional advice

Theoretical rates are an upper bound, not what a device will measure.

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