Distances depend on what line you take in the river (inshore vs fairway etc), so the table below is a guide, most useful for those outings without GPS etc.

Source: St Pauls Boat Club, with addition of FRBC from Google Maps

FRBC to:ReturnOne way
Hammersmith Bridge520260
St Paul’s1,306653
Chiswick Pier4,1082,054
The Bandstand5,4402,720
Barnes Bridge6,3683,184
Chiswick Bridge8,8344,417
UL Boathouse10,8765,438
Kew Rail Bridge11,6085,804
Kew Road Bridge12,9186,459
Brentford Lock14,8827,441
Pink Lodge18,5349,267
Richmond Lock20,83410,417
FRBC to:ReturnOne way
Far end Harrod’s Wharf480240
Mile Post1,804902
Barn Elms2,8481,424
Beverly Brook3,3601,680
Black Buoy3,7701,885
Putney Pier4,7662,383
Putney Bridge5,1322,566
Fulham Rail Bridge5,6422,821
Wandsworth Bridge8,7884,394