Free Embeddable Calculator

<!-- AmCalc Mortgage Calculator Widget -->
<iframe
  src="https://amcalc.com/embed/widget?theme=light&amount=300000&rate=6.5&term=30"
  width="400"
  height="450"
  style="border: 1px solid #e5e7eb; border-radius: 8px; max-width: 100%; overflow: hidden;"
  title="Mortgage Calculator"
  loading="lazy"
></iframe>
<script>
  window.addEventListener('message', function(e) {
    if (e.data && e.data.type === 'amcalc-resize') {
      var iframe = document.querySelector('iframe[src*="amcalc.com/embed"]');
      if (iframe) iframe.style.height = e.data.height + 'px';
    }
  });
</script>