BT Infinity speed checker - how accurate is it?

Apologies if this has been done to death - the BT Infinity speed checker tells that when my exchange (Wandsworth - LSWAN) is converted to FTTC, my broadband's speed "range" will be 36.1 Mbps down and 10.0 up. I'm wondering how exact this is. There's no range quoted, and the only caveat is the words:

"The range is an indication of the speed that other similar lines across the UK have achieved for their broadband service; this is generally within 1-2 Mb higher or lower than your single estimated speed quoted."

Does the fact that no range is quoted mean that I really will get 36.1 +- 1 or 2 Mbps?

In reply to a post by herbgold:

Apologies if this has been done to death - the BT Infinity speed checker tells that when my exchange (Wandsworth - LSWAN) is converted to FTTC, my broadband's speed "range" will be 36.1 Mbps down and 10.0 up. I'm wondering how exact this is. There's no range quoted, and the only caveat is the words:

"The range is an indication of the speed that other similar lines across the UK have achieved for their broadband service; this is generally within 1-2 Mb higher or lower than your single estimated speed quoted."

Does the fact that no range is quoted mean that I really will get 36.1 +- 1 or 2 Mbps?

Possibly! or maybe Probably!

There are quite a few factors that could affect your connection. In general the estimates are pretty good, but if your neighbour runs a generator or compressor in his garage adjacent to the pole, then you may have some problems!

How far from your Green Cabinet are you? Pace out the distance from House to pole to cabinet and add 20m to it.

I have yet to install one of these lines where the estimate wasn't surpassed.

Remember the estimator is talking about connection speed, not actual download speed from websites, which will of course vary as they are spread all over the world

Thank you all for prompt and helpful replies. MHC - it's about 30 metres from my front door to the cabinet (no pole, presumably all underground on this side of the street although there is a pole to feed older houses opposite). So 30+20 = 50 metres.

IN your case forget the 20m and just add a few ... The 20m allows for 7m up the pole, 7m down your wall, the catenary differential and a bit extra.

For yours I would suggest you will get a full 40Mbps sync, 3871x profile and in practice a download of 36500 or more dependent on congestion or any local in house RFI (noise).

Blimey! Thank you.

And once the up to 80 Meg products, if you elect to pay/upgrade a much faster speed than that.

Profile 17a is the tech term, and those people with the unlocked modems are seeing the profile in use, just the product is capped to 40Meg currently.