What’s the Difference Between 32ECT and 200#?

If you are comparing corrugated shipping boxes, two specifications you may encounter are 32 ECT and 200#. They are both used to describe corrugated board performance, but they come from different tests and measure different properties.

The important thing to understand is that 32 ECT does not mean a box can hold 32 pounds, and 200# does not mean a box can hold 200 pounds. Neither specification should be treated as a simple finished-box weight limit.

Instead, 32 ECT focuses on the board's resistance to edgewise compression, while 200# refers to burst strength measured with the Mullen test. Which specification makes sense depends on the box, product, stacking requirements, handling environment, and type of protection needed.

What Does 32 ECT Mean?

ECT stands for Edge Crush Test. The test measures the force required to cause compressive failure of a sample of corrugated board standing on its edge. ECT is commonly expressed in pounds of force per inch of board width, or lb/in.

A 32 ECT board therefore has an edge crush rating of 32 lb/in under the applicable test method. It does not mean that a finished box can hold only 32 pounds or that 32 pounds of weight can be stacked on top of it.

The Fibre Box Association describes ECT as a primary factor in predicting the compression strength of a completed corrugated container. That makes it particularly useful when stacking and box compression are important design considerations.

What Does 200# Mean?

200# typically refers to a corrugated board specification with a minimum burst strength of 200 pounds per square inch, or 200 psi, as measured by the Mullen burst test.

The Mullen test measures the pressure required to rupture the face of a sheet of corrugated board. In other words, it evaluates resistance to a bursting or puncturing force applied to the board surface.

A 200# rating therefore does not mean a box can safely contain 200 pounds of product. Finished-box capacity depends on dimensions, construction, contents, stacking conditions, environmental exposure, and other factors.

32 ECT vs. 200#: What Is the Actual Difference?

The main difference is what the test measures.

Because these tests measure different properties, there is no simple mathematical conversion that says a certain ECT rating always equals a certain Mullen rating. Fibre Box Association guidance specifically notes that no correlation method is available for converting Mullen or burst properties directly into stacking strength.

Are 32 ECT and 200# Equivalent?

Not technically.

You may see 32 ECT and 200# burst specifications discussed together because both are common single-wall corrugated specifications and carrier rules allow boxes to be certified using either ECT or burst-based requirements when the applicable construction and limits are met.

But that does not make 32 ECT and 200# the same material or guarantee identical performance.

For example, current corrugated specification examples show separate Box Maker's Certificates for 32 ECT and 200 psi burst board with different stated size and gross-weight limits. That illustrates why the certifications should not be treated as interchangeable numbers.

When Does 32 ECT Make Sense?

ECT-rated corrugated is especially relevant when efficient stacking and compression performance are important parts of the package design.

A 32 ECT box may be appropriate for many ordinary shipping applications when its dimensions, construction, packed weight, stacking requirements, and distribution environment fall within the intended design.

Potential considerations include:

• Palletized shipments where cartons will carry vertical stacking loads.
• Warehouse storage involving stacked cartons.
• Applications where efficient board construction is important.
• Parcel and distribution applications appropriate for the selected box specification.

The original industry adoption of ECT as an alternate certification method was specifically intended to better address box compression and stacking performance.

When Does 200# Burst Make Sense?

A burst-rated specification may be useful when resistance to rupture, puncture, or forces acting against the face of the corrugated board are important considerations.

Applications involving dense, irregular, or potentially damaging contents may place different demands on a box than a uniform product that primarily needs stacking support.

That does not mean 200# is automatically “stronger” than 32 ECT. It means the board has been specified and tested around a different performance characteristic.

Why You Shouldn't Choose by the Number Alone

Neither 32 ECT nor 200# tells the complete story of a finished corrugated box.

Box performance can also depend on:

• Box dimensions.
• Flute profile.
• Single-wall or multi-wall construction.
• Box style.
• Product weight and weight distribution.
• Internal packaging and support.
• Stacking height and pallet pattern.
• Humidity and moisture exposure.
• Storage duration.
• Shipping and handling conditions.

If the real question is how much product a particular box can safely contain or support, see How Much Weight Can a Corrugated Box Hold? That article explains why finished-box capacity cannot be determined from ECT or burst rating alone.

What Is a Box Maker's Certificate?

Corrugated shipping containers may carry a Box Maker's Certificate, or BMC, printed on the box. The certificate identifies information about the box manufacturer and applicable construction requirements.

Depending on the certification method, the BMC may identify an Edge Crush Test value or a bursting test value along with applicable size and gross-weight limits. Current industry rules define the BMC as certification that applicable construction requirements have been met.

This is another reason not to look at “32 ECT” or “200#” in isolation. The complete specification matters.

ECT vs. Mullen: Want the Deeper Explanation?

The 32 ECT vs. 200# comparison is really a comparison between two different ways of evaluating corrugated board: the Edge Crush Test and the Mullen burst test.

Our ECT vs. Mullen Testing guide takes a deeper look at how the tests are performed, what each result means, how ECT relates to finished-box compression, and why the two ratings should not be directly converted.

The Bottom Line

32 ECT and 200# are not competing versions of the same measurement.

32 ECT measures edgewise compression strength. 200# measures burst strength. Both can be useful corrugated specifications, but they describe different performance characteristics.

The right box should be selected around the actual product, box dimensions, stacking requirements, distribution environment, and type of protection needed—not simply because one number appears larger than another.

Need Help Choosing Corrugated Boxes?

Browse corrugated packaging or Contact Packaging HERO if you need help choosing board strength, box construction, dimensions, or packaging for a specific shipping application.

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