When you purchase bag in box packaging, you may often say that I need 5 liter bag, 20 liter bag etc. These are the capacities of the bags.
For a bag in box manufacturer, they need to convert these capacities into dimensions, such as how long and how wide. So we will talk about the two dimensions of the bag, the outer dimensions and the inner dimensions.
Why are dimensions important?
- Bags of the same capacity can be made into many different dimensions. So manufacturers need the exact dimensions to make bags.
- BIB Bags need to be put in the outer box to use. So the dimensions of the bag need to be carefully designed to match the outer box.
Why there are two dimensions?
Bags will have 4 seal edges after heat sealing by hot pressed tools. Seal edge causes two dimensions.

What are the outer and inner dimensions?
Outer dimensions measure the distance from one point on the outside of the bag and to an opposite point on the outside. Inner dimensions measure the inside of the seal edges

Why are the inner dimensions more accurate?
- The capacity of the bag is calculated by inner dimensions.
- As each factory has its own production process, the width of the seal edge is different. Some are 2cm; some are 3cm, etc. So if the bag is made according to the outer dimensions, there may be errors.
So when you are sourcing bag in box, it is best to inform the suppliers of the inner dimensions or ask them to provide them. In this way, you will avoid any problems due to dimensions.