rest is gravy

(the) rest is gravy

Fig. Any additional money received is just an easily acquired bonus. There is some cost involved in buying the raw materials, and the cost of manufacturing is negligible. When we pay off the costs, the rest is gravy.
See also: gravy, rest
References in periodicals archive ?
At pounds 1,447 an hour, it will only take two and a half days to pay off the bike loan and the rest is gravy.