CBM Calculation in Export: The Simple Formula Every Exporter Must Know In export business, CBM (Cubic Meter) is one of the most important calculations for container planning, freight cost estimation, and loading quantity. If you know your CBM, you can quickly estimate how many cartons/boxes will fit in a 20ft or 40ft container and avoid costly loading mistakes. ✅ What is CBM? CBM = total volume of your cargo in cubic meters. It tells you how much space your shipment will occupy. ✅ CBM Formula (f