How to Find the Center Without Doing the Math
Anyone who knows me knows that I don’t like to follow convention. I swear I don’t do it to be ornery (though my wife might disagree), I just enjoy viewing things from different angles. I always take a different route when I can and like to approach life the same way. One of my differing viewpoints is on measuring. For some people the measurement is the measurement and that’s it. For me, not so much. It doesn’t seem like much of a hill to die on, but I think it is at least worth discussing. Measuring with tape measures and using some system like imperial or metric to communicate those measurements with others is important, but it isn’t the only way to accomplish many tasks. One of the most common places to subvert mathematical conventions is in dividing spaces evenly, and a great example is finding the center of a piece by dividing a space in two.
Finding the center with math can be simple – half of 24″ is 12″. But, it can be hard too. Real quick, tell me the center of 157-13/16″. The answer will take some math and possibly a calculator to get to 78.90625″ or 78-29/32″, and then you need to find that on a tape measure – more math to figure out that 29/32″ is just between 7/8″ and 15/16″and isn’t even marked on your tape measure. The conventional approach would be to do the math, mark the measurement, and double check the math by measuring from each side to verify that the center mark is the same distance from each edge. But, I am here to tell you that you can skip the math part.
The measurement or the actual number on the tape measure is somewhat arbitrary at this point. All that is needed is for both halves to be the same, whether or not it lines up with a mark on a tape measure doesn’t matter. Think of it like this, that center point is going to be in the same place no matter what measuring system you use. The measuring system is just a way for you to communicate a number from piece to piece or to someone else.
So, how do you find the center without doing the math? The answer is pretty simple. Skip the math part and just go straight to the verifying part. All you need is a tape measure and one good eye. Here’s how to do it:
1) Look at the piece and put a mark in what looks to be the center. Maybe you have a great eye, maybe you are done.
2) Measure to that mark from one side. It will most likely be a wacky, non-conformist number like 28-15/16″, plus a skosh. Simplify your life and move that mark to something easy and something on the tape measure, in this case 29″.
3) Measure from the other side towards the center and mark 29″ again. Now you will have two marks on your piece. If you have a good eye, those two marks will be very close together. If not, pick another number that will get those marks closer together. For example, those two marks might be about 6″ apart, so add 3″ or subtract 3″ (depending on if they overlap or not) to each side and remark. Now they will be close together. Still no math.
4) If you are only roughly splitting the piece in two, it is easy enough to eyeball and mark the center at this point, since there is very little distance between the two marks. If you need to be accurate, just change your measurement a little. If your marks are about 1/2″ apart, change it by 1/4″ on each side. At some point the numbers will be exactly the same or they will be 1/16″ or less off. Once you get to that point, you have no choice but to eyeball it and put a mark in between the marks.
I love to use this system and smile a little bit inside when I do it, feeling like I know some secret no one else does. I know it’s not the case, but I still think it is fun to find the center without all the official math. Heck, I could even do the same thing with just a random stick if I needed too. On a recent project, I was cutting it very close on length and needed to make sure my layout was in the middle of the slab, and I got a chance to use my “no measuring” system again, and this time I got it on video. Check out the following video where I show my measuring marvel in real life: