How to find the center of a board

Center by length

Measure the full length and divide by two. For a board 35 3/8" long, half is 17 11/16", which falls right on a sixteenth mark. Hook your tape on the end and mark that distance.

Many results land between marks. Half of 23 17/32" is exactly 11 49/64", which isn't on a standard tape. Round to the closest mark, 11 3/4" in this case, and you're off by less than 1/64". The tape measure calculator does this and shows the mark on a ruler.

Center by width, no math

Lay your tape across the board at an angle, with the 0 at one edge and a number that divides easily by two at the other edge. On a board 5 3/8" wide, tilt the tape until the 6" line touches the far edge. Mark at 3". Do the same a little further along, then connect the marks with a straightedge for the center line.

Tips

Use a sharp pencil or a marking knife so the line is thin. Measure from the same end each time, and mark with a small V, with the point on the exact spot. If you need several evenly spaced marks and not just the middle, use the equal spacing calculator.