Here is a quick formula.

wingspan divided by four. Then take number and measure from the wingtips in. That will give you the middle of each wing panel.

Measure the wing cord from that spot. Then take a percentage of the cord, you can start with 28%. So if your cord is 10" you will balance 2.8" from the leading edge In the middle of the wing.

If you want to balance the plane closer in on the fuse all you need to do is draw a straight line from your marks in the middle.

This will compensate for any taper in the wing. and it works on all airplanes