Measurement Guides
Practical, step-by-step guides to reading, converting and choosing metric and inch sizes.
All Guides
Metric vs Imperial: How the Two Systems WorkHow mm, cm and m relate to inches, feet and miles — and why 1 inch is exactly 25.4 mm.Wrench and Socket Size Chart: SAE vs MetricCommon wrench sizes in both systems, and which pairs are close enough to swap.Paper Sizes in Inches and MMA0–A6, Letter, Legal and Tabloid, plus the A4 vs Letter printing trap.3D Printer Filament and Nozzle Sizes in Inches1.75 and 2.85 mm filament, nozzles and layer heights converted to inches.Rainfall MM to InchesRain chart, what 1 mm of rain means, and light, moderate and heavy rain.How to Read a Tape Measure (Inches and Millimeters)What every line means — inch fractions down to 1/16″, the metric side, and converting between them.Drill Bit Size Chart: Fractional Inch to MetricMillimeter equivalents for 1/16″–1/2″ bits, inches for 1–13 mm bits, and which sizes you can swap.Metric Bolt Sizes in Inches (M3–M12)Thread pitch (mm, with TPI equivalents), wrench and hex key sizes, tap drills and clearance holes.Pipe Sizes in Inches and MMWhy a 1/2″ pipe is not 1/2″ — NPS, DN and copper sizes with real outside diameters.TV and Monitor Screen Sizes in CM24″ to 85″ screens in cm, with the real width and height of each.Ring Sizes and Bead Sizes in MM and InchesUS ring sizes as diameter and circumference, and bead sizes in inches.
Printable Charts
Have a topic you would like covered? Let us know.