Time.frameCount

Description

The total number of frames that have passed (Read Only).

using UnityEngine;

public class Example : MonoBehaviour
{
    // Makes sure that RecalculateValue only performs
    // some operations once per frame and no more.
    static private int lastRecalculation = -1;

    static void RecalculateValue()
    {
        if (lastRecalculation == Time.frameCount)
            return;
        //  ProcessData.AndDoSomeCalculations();
    }
}

Note: frameCount starts once all Awake functions have finished. The frameCount value will be undefined during Awake functions.