Measuring small objects with a Vernier caliper is a lot more accurate than using a ruler, but how to read a manual Vernier caliper is a mystery to most.

Step 1: Manual calipers typically have a measurement marked along both the top and bottom edge. Sometimes one scale is in inches while the other is in millimeters; either way, the bottom scale, with more hash marks, is the main scale.

Step 2: Look for the fractional or decimal indicator found to the far right of the scale to determine the fractional value of each hash mark. If there is no indicator, count the hash marks to determine their value, just like on a ruler.

Step 3: Place the item to be measured between the jaws of the caliper. Use the bottom set of jaws on the caliper for measuring the exterior diameter of an object and use the top set of jaws for measuring the interior of an object. Slide the jaws firmly against the sides of the object.

Step 4: The movable scale attached to the caliper’s right jaw is called the Vernier scale. Locate the numeric digit on the main scale printed closest to the left of the zero line on the Vernier scale. Big numbers are the whole numbers and the hash marks represent a fraction of the whole number. Note the number located on the main scale to the left of the zero line on the Vernier scale.

Step 5: Count the hash marks between the whole number on the main scale and the zero on the Vernier scale. Hash marks typically represent tenths of an inch or a millimeter — depending on what caliper is being used. For example: If the whole number is 4 and there are three hash marks between the 4 and the Vernier scale zero, the measurement would be 4.3.

Step 6: Look at the marks along the Vernier scale. Find the first hash mark on the Vernier scale to the right of the zero that is aligned perfectly with a hash mark on the main scale. Using the same method as before make note of the number and the hash marks on the Vernier scale to the left of the aligned set of hash marks. If the whole number is 2 and there is one hash mark between it and the set of aligned marks, the number for the Vernier scale would be 2.1.

Step 7: The Vernier scale typically represents hundredths of an inch or millimeter, so move the decimal from the Vernier reading two spaces to the left, making the example .021.

Step 8: Add the number acquired from the main scale with the number acquired from the Vernier scale to get the exact measurement of the item. Using the examples given, the measurement would be 4.3 + .021 = 4.321.

Step 9: For calipers with scales that are not in tenths and hundredths, simple division and addition using the caliper’s fractional indicator should result in accurate measurements.

— Have a home improvement question for Fix-It Chick? Email it to Linda Cottin at hardware@sunflower.com.