Good, and unusually well provided for a village this size. There is a village primary that carries the place name. There is a genuine choice of secondaries in two directions. There are grammar schools within reach for families who want that route. Very little about Kingskerswell is remarkable, which makes the schools the exception worth knowing about before you look at anything else.
Kingskerswell Church of England Primary School is the state primary in the area, and the Key Stage 2 maths average across mainstream state primaries around here comes out at a score of 104. That sits above the expected standard rather than dramatically clear of it, which is what a settled village primary with a stable intake tends to look like. Parents who want alternatives are looking at nearby villages and the edges of Newton Abbot and Torquay, where Abbotskerswell Primary School and the Torquay primaries such as Shiphay Learning Academy are the sort of thing that comes up on the map.
Secondary is where the real choice appears. Three mainstream state secondaries serve the area, with a pupil-weighted Attainment 8 score of around 60 between them. Coombeshead Academy and Newton Abbot College sit on the Newton Abbot side, Torquay Academy on the other, and the two selective schools, Torquay Boys' Grammar School and Torquay Girls' Grammar School, are close enough that the eleven-plus is a live conversation in this village rather than a theoretical one. Being equidistant between two towns is normally a curse. On schools it works out.
Across Devon as a whole, Ofsted has graded 138 of 172 settings as good or better, which is four in five, with three rated outstanding, 31 requiring improvement and three inadequate. Those counts cover the whole local authority rather than Kingskerswell specifically, so they describe the pool a family is choosing from, not the two or three schools they will actually apply to. A further 135 settings hold no published grade yet, which means exactly that and nothing worse.
The usual warning applies harder here than in most places. Being able to see a school from your kitchen window has never guaranteed a place at it, and with grammar schools in the mix the allocation question splits into two entirely separate processes running to different rules. Check the admissions arrangements for the specific schools you care about, in the specific year you are applying, before you let a school name influence which house you buy. Families who work that out in advance make a calm decision. Families who work it out in March make a different one.
Schools are the strongest thing Kingskerswell has going for it, and the reason for that is geography rather than any single institution. The village primary is solid, and the secondary choice is broader than a place this size has any right to expect.