ECT vs Burst Strength: Choosing the Right Box Strength

ECT and burst strength are the two ways corrugated box strength is rated. Picking the right rating keeps your products safe without overpaying for board you do not need. Here is what each means and how to choose.

What is ECT?

Edge Crush Test (ECT) measures how much stacking force a box wall can bear on its edge. It predicts stacking strength - important for palletizing and warehousing. Higher ECT means more boxes can be stacked safely.

What is burst strength?

Burst (Mullen) strength measures the pressure a box wall can take before rupturing. It reflects resistance to punctures and rough handling - useful for heavy or dense products.

ECT vs burst: which to use

• ECT - best when stacking and shipping efficiency matter; lighter, more sustainable.
• Burst - best for heavy, dense products or rough handling.

Flute choice also affects strength - see our flute types guide.

Matching strength to product

Match rating to product weight, stacking, and shipping conditions. Do not over-spec - it wastes money and material. See our right-size packaging guide and the complete guide to custom printed boxes.

Frequently asked questions

Is ECT or burst better?

Neither is universally better - ECT suits stacking and lighter boxes; burst suits heavy or roughly handled goods.

Does higher strength always help?

No. Over-speccing adds cost and weight; match the rating to your actual needs.

How does flute affect strength?

Larger and double-wall flutes add stacking strength and cushioning.

Choose the right strength

Protect products without overpaying. Explore our custom corrugated boxes or the e-commerce boxes collection.