good news.
It also depends on the 'quality' your photos are set at, each brand of camera does this in a different way.
Mine has four settings - high, fine, normal and economy and I leave it on fine for me, as it gets great detail. Fuji cameras have a setting that varies the actual pixels used (1million, 3million etc).
So you're probably on normal quality ( perfectly acceptable for holiday snaps ) at that size which is fine too.
Do a couple of tests first.