JSFiddle - React, Tailwind, and code Playground

HTML

<form name="CalorieForm">
    <input type="checkbox" name="gf"> Groente en fruit <br />
      &nbsp <input type="radio" name="gf1" value="60"> Appel (60 kcal per appel) <br />
      &nbsp <input type="radio" name="gf1" value="26"> Paprika (26 kcal per paprika) <br />
    <br>
    <input type="checkbox" name="bpp"> Brood, pasta en peelvruchten <br />
      &nbsp <input type="radio" name="bpp1" value="111"> Zilvervliesrijst (111 kcal per 100 gram) <br />
      &nbsp <input type="radio" name="bpp1" value="24"> Sperziebonen(24 kcal per 100 gram)<br />
    <br>    <br>
    <input type="button" value="Bereken de calorieën" name="totaal" onClick="BerekeningCalorie()"> <input type="reset" value="Reset" />
    <br>
    <br>
    Aantal calorieën: <input type="text" name="Calorie" size="20"><br />
 </form>

JavaScript

function BerekeningCalorie() {
  var totaal = 0;
  if(document.CalorieForm.gf.checked)
    totaal += parseInt(document.CalorieForm.gf1.value || 60, 10);
    
  if(document.CalorieForm.bpp.checked)
    totaal += parseInt(document.CalorieForm.bpp1.value || 24, 10);
    
  document.CalorieForm.Calorie.value = totaal;
}