Your true internet speed is up to 12% higher than the advertised speed.

As explained at the most accurate speed test it was concluded that:

- when the advertised speed is 50 Mbps, the true speed is 56 Mbps
- when the advertised speed is 75 Mbps, the true speed is 84 Mbps

When only the 50 Mbps measurement results were known, it was not possible to determine whether the actual speed in absolute or percentage terms was higher than advertised.

However based on the numbers mentioned above it is clear that the true speed is 12% higher than the advertised speed.

During the ultimate home network test of 2022, the advertised speed was 100 Mbps. Not surprisingly, even now the actual internet speed is 12% higher than advertised.

## Why 12% higher

Mainstream speed tests are a little bit conservative (probably due to an outdated assumption made by Ookla). They know that the internet speed you experience is lower than the theoretical bandwidth due to retransmitted packet headers and data packets.

Cloudflare, a mainstream speed test which gives as result the advertised speed, state at their about page: Speed is measured by downloading/uploading progressively larger files and taking the 90th percentile speed.

Suppose the advertised internet speed is 100 Mbps. With the extra 12%, the true internet speed is 112 Mbps. 90% of 112 Mbps = 100.8 Mbps. That is roughly the advertised internet speed.

## Each ISP delivers 12% more than advertised

As expected the results of the Ookla speed test are similar to those of Cloudflare. This means that Ookla nowadays still calculates the measured speed by taking 90% of the maximum measured speed.

This is important because almost every ISP recommends the Ookla speed test, or uses a clone of the Ookla speed test.

It is therefore very likely that each ISP will deliver 12% more than advertised.

## How to measure your true internet speed

Based on the The ultimate speed test test 2021 it is clear that if you want to know your true internet speed, you should use SpeedOf.me and check the max download speed. With an advertised speed of 100 Mbps, SpeedOf.me measures 111.52 Mbps.

SpeedOf.me is the only speed test that correctly measures your true internet speed.