Easily Estimate Plate Steel Weight

Easily Estimate Steel Plate Weight

“How much do you think that weighs?” and the guesses go around… A familiar scene?? Here’s how to easily estimate steel plate weight and add another tool to your brain tool box.

Whenever this topic comes up all I’ve ever heard was people repeat the familiar ’40LBS per foot’ or the more baffling ‘0.2904LBS per cubic inch’ as if that in itself explained everything. I struggle with quickly doing math in my head and I never fully grasped how some people can so easily and quickly manipulate those numbers to apply to what’s in front of them.

It wasn’t until a co-worker recently explained and drew this out for me that it really made sense. Yes, pictures help! I know many of you out there do not have trouble with easily estimating steel weights – especially if you do it several times a day – but I also know there are some like me, who’ve struggled. It’s those people I’m talking to and I hope this ‘clicks’ for you too.

Easily Estimate Plate Steel Weight

Here’s what he drew…

Easily Estimate Steel Plate Weight

The familiar 40LBS per 1″ square foot is still the basis for this explanation. (shown in the top right corner). But the genus of this drawing is breaking that number down into commonly used steel thicknesses.

NOTE: This is considered approximate. Used for estimation purposes only.

Recently I had to move a 6′ by 16′ piece of 1 1/4″ QT 100 plate and was actually excited and amazed to put this to use.

If I go 6′ X 16′ = 96 Square feet of plate.

Using the diagram I know that an 1 1/4″ square foot of plate is 50 LBS. Easy right?

So my 96 square feet X 50LBS/sqft the plate = 4800LBS

Then I can round to 5000LBS for my crane and rigging and be well within their weight limits.

I’m going to post this under Tools because ‘tools’ like this are just as critical as any other wrench, centre finder or helmet. Equipping the toolbox in our brains is just as, if not more important than physical shiny tools.

Stay awesome and safe,


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