The Quick, Cheap and EASY Way to Find the Center of a Circle

Gordon is building a new fixed-post mirror-grinding machine, and had to find the center of a big round turntable top he is building. Using little more than a "tricky" piece of paper, Gordon shares with you how to pinpoint the center of any circle. Amazingly, you don't need to measure anything! Use Gordon's trick for woodworking projects, scrapbooking, crafts, or any place you need to find the exact center of a circle.

[mysleniedozwolone]

Hey Gordon, just wanted to thank you, you made my work much easier now ❤️

[johnkashka]

Great tip! I also have to find the center of a circle all the time, I have come up with many ways, but yours is by far the simplest.

[zobook]

i'm 9 years late but this video was just exactly what i needed. My son is about to paint a clock-face on a piece of circular MDF but because is laser-cut there is no center point mark. This work great!!

[aimeedull]

Thank you for this hint!! It was easy and accurate, often those two words are rarely used together!! You saved my sanity! A. Dull

[ultrametric]

A refinement on your method - you need a piece of cardboard or the like with at least one accurately square corner and perfectly rectilinear edges that meet there. You can even use a large carpenter's square. Tape the device so that the accurately square corner is coincident with the rim. Now mark where the two edges cross the rim. These two points are necessarily diametrically opposed. It works for any position of the tool, as long as the corner is exactly on the rim. Do it for a couple of positions and you'll have several diameters which meet in the center. Love your videos!

[fredthemagnificent]

That’s a really good tip!!! Just tried it and I did some extra reference points and it was surprisingly accurate. Great for general DIY. Thank you for sharing.

[misswibb]

BRAVO! So simple. You’ve saved me a little $ and a lot of time. Thank you!!

[mysteriousplankton]

So simple. I needed for a woodworking project and now it's a piece of cake.

[WoodfulProjects]

This is indeed the quick, easiest and cheapest method I've seen :). I usually use the "1. draw a line, 2. draw the perpendicular on the middle of this line" then repeat 2 or 3 times which will give you the center. You method is exactly the same but it removes the errors due to lack of accuracy while drawing the perpendicular line (which should be in the middle and 90°). Thanks for sharing. I think I'll remember this trick for long :)

[rcdavidk]

Brilliant. You used Euclidean geometry and created an isosceles triangle out of a piece of paper. Very nice. Thank you.

[Crackpot_Astronaut]

I have spent so much time trying to Google instructions on how to place table legs on a round table. I know that isn't what you intended here, but this brilliant! Most helpful video out there, for sure. Thank you!

[JagiChan]

Awesome. That definitely is the cheapest method. Thanks for the detailed explanation and demonstration.

[Jay-phtv]

Thank you so much for this very informative video. Made it very clear and understandable.

[astro_zane]

This really does work. Have used it to find the center of turntables and Dob bearings. Thanks Gordon!

[kdawdy]

You saved me! I had none of the tools many others used.

[JustinDGates]

Very cool!  Alternatively, I was taught to trace the circular object onto a larger sheet of paper, carefully cut out the circle from the paper, then carefully fold the circle in half a few times over until you're left with a "pizza slice" sector.  Using scissors, just snip a tiny portion off the small end of the "slice", then unfold.  The new hole is the center of the paper circle, which you can carefully realign over your circular object and mark.  Cheers!

[muddyfunker]

Quite simply brilliant.

I love youtube for videos like this.

Thanks buddy, this is a great idea and demo 👍

[larryseibold]

Excellent. I like that you did three vs two lines of intersection so that you could get a rough idea of the uncertainty center circle (dot if perfect). The optimization/elegance of techniques like this is to figure out how to work with imperfect tools resulting in the greatest accuracy in the minimum of time. I will add one obvious point: the short edge of the paper needs to be less than the diameter of the circle, ideally about 60% of the diameter for maximum accuracy.

[bowlineobama]

Awesome trick!!! I will remember this for a long time. Thanks.

[Grosminet]

Thankyou so much for making this so easy to do!