Embed the CBM Calculator
Cubic meters of a shipment, and the chargeable weight that follows from it — the larger of actual and volumetric, which is what you pay on. Set the values it should open on, then copy the iframe. Your visitors can change them; the widget recomputes against Rule Calculator and never touches your page.
Opening values
Set what the widget shows before anyone touches it. Leave a field as it is and it stays out of the URL.
Preview
Paste this
<iframe src="https://rulecalculators.com/embed/cbm" width="100%" height="1020" style="border:1px solid #e5e5e5;border-radius:12px" loading="lazy" title="CBM Calculator"></iframe>
<p style="font:13px/1.5 system-ui,sans-serif;color:#666;margin:6px 0 0"><a href="https://rulecalculators.com/calc/cbm" style="color:#666">CBM Calculator</a> by <a href="https://rulecalculators.com" style="color:#666">Rule Calculator</a></p>Free for commercial use. The one condition is the credit link inside the widget, which is how the calculator stays free. Want the numbers in your own markup instead? The same calculator is a JSON endpoint, or see the full CBM Calculator page with its sources and working.