When measuring with a dial caliper, most skilled operators are only accurate to what amount?

• A. 0.1 mm
• B. 0.05 mm
• C. 0.2 mm
• D. 1.0 mm

Answer: (A)

When you use a dial caliper, the practical limit on how accurately you can read a measurement isn’t just the instrument’s marks—it’s how precisely you read and position it. Even with a dial showing fine increments, human reading errors (parallax, misalignment of the jaws, ensuring the jaws aren’t tilted, and stopping at exactly the right point) add up. In typical maintenance work, skilled operators rely on a realistic, repeatable accuracy around one-tenth of a millimeter. That makes 0.1 mm the best choice among the options for a reliable, everyday measurement. Values like 0.05 mm assume near-perfect reading conditions that aren’t always achievable in practice, while 0.2 mm and 1.0 mm would be noticeably too coarse for most measurements with a dial caliper.