How can I update my state to assign a new value to an object?

Below is some logic to my current code that currently works as expected.

import react from 'react'
const [userBirthday,setUserBirthday] = useState()

    function calculateAgeTurning() {
    let ageToBe = new Date().getFullYear() - userBirthday.substring(0, 4);

    return ageToBe;
    }

    function addBirthday(url) {
    let newAge = calculateAgeTurning();

    const newBirthday = {
        id: uuidv1(),
        Name: name,
        AgeTurning: newAge,
        image: url,
    };

    setAllBirthdays((prevState) => [...prevState, newBirthday]);

    setIsAddBirthdayShown(false);
    }

However I would like to store the users new age in some state.

What I am expecting is when the user presses a button it will call addBirthday() which then calls calculateAgeTurning(), updates my newAge State and I then set my AgeTurning to the users new age in my newBirthday object. But my state never updates and I constantly get 0 when I console log it. What am I not understanding?

import react from 'react'
const [userBirthday,setUserBirthday] = useState("")
const [userNewAge, setUserNewAge] = useState(0);

  function calculateAgeTurning() {
    let ageToBe = new Date().getFullYear() - userBirthday.substring(0, 4);

    setUserNewAge(ageToBe);
  }

  function addBirthday(url) {

    calculateAgeTurning();

    const newBirthday = {
      id: uuidv1(),
      Name: name,
      AgeTurning: userNewAge,
      image: url,
    };

    setAllBirthdays((prevState) => [...prevState, newBirthday]);

    setIsAddBirthdayShown(false);
  }

console.log(newAge) //0