To make it easy, the distances between the stations that we use on the GCR are:
Loughborough Central - 0 miles
Quorn - 2 miles 3 chains
Swithland Sidings - 4 miles 16 chains
Rothley - 4 miles 66 chains
Leicester North - 7 miles 51 chains
That's just between the stations - we do use the actual Manchester-London mileposts for location marking (Loughborough being approx MP 93 and Leicester MP 100 as Zoe has said).