Measuring & layout

This hub is about getting the number right before you cut, drill or hang anything. It covers tape measures, squares, levels, lasers, calipers and gauges, plus the charts you need to turn one unit into another.

Most measuring mistakes aren't about the tool. They come from reading the wrong mark, mixing up decimals and fractions, or trusting a level that's off. So the guides explain how to read each tool, and how to check that it's telling the truth.

How to pick a guide:

• Stuck on a number like .625? Read what is .625 on a tape measure, or use the fraction to decimal converter.
• New to a tape measure? Start with how to read a tape measure.
• Laying out a wall or a shelf? Go to layout and squares, then levels.
• Measuring small parts? See calipers and gauges.

Each cluster starts with one main guide. The converter and printable chart sit beside them for quick checks in the shop.

Safety basics for this job

• Let a tape retract slowly. A blade that snaps back can cut fingers. Guide it in by hand.
• Set ladders at a 4-to-1 angle. OSHA says the base should sit about one-quarter of the working length out from the wall.
• Don't stare into a laser level's beam. Staring into even a low-power beam can hurt your eyes. Never point it at people, since the glare can dazzle them.
• Mark, then check what's behind. Before you drill on a layout mark, check for pipes and wires in the wall.