BT wholesale speed tester

[#1]

Does anyone know how many Mbs the BT tester users per test on FTTC ?
The reason for asking is that, since recently upgrading to fibre I have, ( of course ! ) , been doing lots of speed tests and have noticed that Gigb usage is amazingly high
The only change to my usual usage being the large numbers of speed tests so I guess they are the culprits and I should control my enthusiasm and limit their usage.
Mike (edgeways)

[#2]

install networx and check it

[#3]

Thanks Old Jim.
I Googled  Networx  but a couple of the down load sites looked a bit iffy so I checked the Mb usage of the speed tester in a simple way.
I first looked up my current usage, then did a BT speed test and then waited for the PN usage tool to catch up, without any significant net use in between. The result is that at 61.5 Mb download speed, the BT tester seems to use around 125 Mb. This seems to be in keeping with downloading a test file for a few seconds at that speed.  Good job I splashed out on unlimited !
Thanks for your help anyway.
Mike (edgeways)