To identify “service” during the American Revolution, we generally look at those born between the 1710s and the 1760s. However, that’s all types of service. If we narrow it down to military service, what ages are involved?
Militia service requirements provide a good guideline for the Army. Connecticut required men to serve between ages 16 and 60. The Museum of the American Revolution places the ages for Continental service between 15 and 40, which would correspond with the more intense demands of that service.
Ages for the Navy (and privateers) are harder to pinpoint. Compiled Military Service Records for the Navy do not include reference to age. Cabin boys seem to have been in the 10-15 year old age range. In an article on the Massachusetts Society Sons of the American Revolution website, Charles R. Lampson mentions a 14 year old receiving a significant share of a prize in 1779. Officers were apparently in their 30s to 40s. Dudley Saltonstall was 38 on his first major voyage as captain. John Paul Jones was 30.
In short, while there is some variation, ancestors between 16-mid 40s are likely to have active military service.