How Much Can a Custom Bulk Bag Hold?

When you’re choosing bulk bags, capacity is key. The right bag should hold the perfect amount for your product safely, efficiently and without landing you with wasted space or extra costs.

Here’s how to work out what your bulk bag can really handle – and why a custom design can make all the difference.

What Does “Capacity” Actually Mean?

“Capacity” covers three things:

Dimensions: Your bag’s height, width and depth.
Material density: How heavy your product is compared to its size.
Safe Working Load (SWL): The maximum weight it can carry safely.

A custom bulk bag lets you match all three to exactly what you need, whether you’re handling lightweight agricultural waste or high-density minerals.

Dimensions: How Big Is a Standard Bulk Bag?

Most standard bags hold around one cubic metre (about 1,000 litres). For your medium-density materials, that usually means 1 to 1.5 tonnes. (It’ll mean slightly more or less for heavier or lighter materials.)

Why Does Material Density Matter?

Knowing your product’s density helps you choose a bag with the right SWL – keeping your loads safe and stopping pricey overloading. Two bags of the same size can carry very different weights. Like these:

Sand, at around 1,600 kg/m³, will fill a 1 m³ bag to about 1.6 tonnes.
Plastic pellets, at around 900 kg/m³, reach only 900 kg.
Light fibres or foam might barely reach 300 kg.

What’s the Role of Safe Working Load (SWL)?

SWL ratings usually range from 500 to 2,000 kg. Even if your product fits by volume, using a bag with too low an SWL can cause your bag to fail.

For heavy-duty use, it’s a good idea to go for specialised construction, extra stitching, or reinforced lift loops to handle your higher loads safely.

Does Bag Construction Affect Capacity?

Absolutely. How your bag’s made can make a huge difference to both its safe working load and how efficiently you can store, stack and move it.

Fabric grade, stitching quality and lifting loop design will also play a key part in your bag’s overall strength and durability.

U-Panel Bulk Bags use a continuous “U”-shaped panel for the base and two sides, creating strong seams and high load ratings. This strength can mean fewer bags for heavy products – reducing your packing and transport costs.
Four-Panel Bulk Bags are stitched from four separate panels. They hold their shape well, making them ideal if you want to stack and store neatly.
Circular Woven Bulk Bags are made from a single tube of woven fabric with no side seams. They’re really cost-effective to produce, easy for you to lift, and can handle high vertical pressure if you need tall stacking.

Make Capacity Work for You

A custom bulk bag can hold anything from a few hundred kilos to over two tonnes. (The actual capacity will depend on things like your density, flow behaviour, construction and safety limits).

At d.a.pak, we design every FIBC to exactly match your product, handling process, and budget – so you always get the safest, most cost-effective solution possible.

Need help finding the right solution for you? Just ask our expert team.

Speak to our experts today