I was told 2.5 is average, but mine is 29 months and still naps 2-3 hours in the afternoons, although she only gets 1 hour on nursery days. We do on occasion skip the nap to enable a full day out, but she is usually shattered and cranky that evening so we don't do it too often. She tells us every day that she doesn't need a nap! I'm hoping she'll have them for some time yet...