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SG DSL Speed Calculator

About the SG DSL Speed Calculator
The SG DSL Speed Calculator is a tool for quick estimation of the maximum attainable ADSL/ADSL2+/VDSL sync speed based on signal attenuation. To use the calculator simply fill in the downstream attenuation number (dB) from your DSL modem, and all other values will be calculated automatically. For additional information on signal levels, attenuation and SNR, please read our DSL FAQ.

To use, simply plug in your actual downstream attenuation, as reported in your DSL modem/router stats page. To obtain your router line stats, you will have to login using your browser. We have an extensive database of modems/routers with their corresponding IP addresses and default passwords available -here-.

DSL Maximum Speed Calculator
Downstream Attenuation dB
Cable loss dB/km (default=13.81)

Approximate Distance meters
ADSL Max Speed kbps
ADSL2+ Max Speed kbps
VDSL2 Max Speed kbps

Attenuation is the reduction in signal strength on your line, sometimes also refered to as "loop loss". While it is related to the length of the line from the exchange, it varies depending on the actual wire gauge, material, as well as the frequency. Attenuation is calculated differently for ADSL and ADSL2, it is common to see a 3-4 db increase when moving from ADSL1 to ADSL2+.
Rate adaptive DSL makes use of any spare SNR margin - the higher your SNR, the better your speeds will be.
Reach Extended ADSL (RE-ADSL2+) provides approximately 500 meters (~1,640 feet) additional loop reach.
Some VDSL2 modems may report 3 very different attenuation values for the D1, D2 and D3 frequency bands instead of a single value. The 8c profile should be used with the above calculation if possible.

This calculator assumes 13.81 db/km average loss (accepted constant for 26AWG wire) by default. For different gauge wires, please check this FAQ.

Actual rates can vary significantly from these theoretical figures (around 10%). The above figures are compiled average sync rates based on users feedback, as well as calculations by Richard Moulynox from the Whirpool forums, thank you! Considering protocols overhead, best case scenario should be able to achieve ~90% of the maximum theoretical speeds in actual throughput speed testing. Please drop us a line on our forums with any feedback, or if you feel we can improve this tool.

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