I have to be honest I cant remember exactly. If I recall it hasnt taken more than a couple of hours there and back (walking time only. add extra in pub). As it is the same route there and back (i.e not circular) then you can always cut short or continue for longer. If you google ''barcombe mills...
Fairly flat and easy but I like to park up, walk along a disused railway to the anchor at Barcombe. Have a large dinner with couple of beers. Then continue along the Ouse to a waterfall and back to car. Can't remember the hamlet where we park but there is a disused railway station there.