A 4 outer is 10.5:1 against hitting with one card to come. To call the turn bet you need to be getting 10.5:1 odds (or better) on your bet (it will come in 1 in 11.5 times). Same for your river bet.

A 4 outer is 5.25:1 against hitting with two cards to come but you can’t use those odds to evaluate your call on the turn unless it puts everyone All in.