Tune the strings open. A fretted note may be a bit off from exact pitch depending on your intonation, nut slotting and even technique. Some variation from 0 can be expected on fretted notes, but it should not be a lot.

Depending on the quality of the acoustic, it might be a lot. It would probably benefit from a set up. Get luthier to check your nut slots, and do whatever he may for intonation. It will be well worth the money.