Reading a tape measure is easy if you know what to look for
Learning how to read a tape measure is one of the first things any professional or DIYer must learn. If the old adage "measure twice, cut once" is true, you'll never cut if you don't know what you're reading.
Parts of a tape measure
Before we read about the tape measure, let's review some basics. Tape measures may vary in appearance with some parts and features, but most fall into these general categories:
- Hook : Tape end that grabs or pushes material
- Blade : The "tape measure" in a tape measure, with measurements printed on it
- Housing : Plastic or metal housing with blade rolled back
- Lock : The slide on the front of the tape that, when you press it, prevents it from going back
- Clip (or Belt Clip) : A metal piece on the side that clips the tape to a belt, pocket, or bag
- Overmolding : Rubber material on the shell for added comfort and drop protection
How to Read a Tape Measure in Inches and Feet
A tape measure does the most basic work in inches and feet. These are the sharpest, boldest markings you'll see. It is numbered every inch of it from the hook, and then additional numbers per foot.
Once you get past 1 foot, the inch markers continue to increment by 13, 14, 15, etc. instead of starting at 1. Some tapes have an extra smaller number that coincides with the last foot mark you hit. For example, it might tell you that 22 inches is also 1 foot 10 inches.
Between each full blade width inch mark, there is a series of smaller marks. They come in different sizes to help you easily identify which is which. Some tapes even have scores printed on them, making them easier to read.
When you're learning how to read a tape measure, be aware that most people divide each inch into 16 parts. In other words, you can read a tape measure with an accuracy of 1/16th of an inch. The 1/2 inch mark is longest, followed by the 1/4 inch mark, then the 1/8 inch mark. The 1/16" mark is the shortest. Reading from one inch forward, the pattern looks like this (the markings on the blade are solid):
- — 1/16
- — 1/8
- — 3/16
- —- 1/4
- — 5/16
- — 3/8
- — 7/16
- ——— 1/2
- — 9/16
- — 5/8
- — 11/16
- —- 3/4
- — 13/16
- — 7/8
- — 15/16
How to read a tape measure in millimeters (mm)
Things are different if you're learning how to read a tape measure in millimeters. A metric tape measure breaks down to 10 millimeters per centimeter. Counting like standard tapes, these don't have foot indicators, but are red or otherwise highlighted every 10cm. they may also be marked with gauges
As you read between each centimeter mark, each short mark is 1 mm and the 5th mark is usually longer to help your eye find the middle easily. The good thing is that you don't have boundaries between scores. Here's an easier decimal conversion. 13 cm and 4 mm is 13.4 cm.
Some tape measures — and there aren't many — can even take both measurements on the same tape. While this is convenient, it also messes up the visibility of the markers in our opinion. We rarely need both metric and standard. If you're working with materials that require metric measurements, make sure you have at least one of these tapes on hand. In either case – pay attention to the label on the tape itself and buy the correct one!
How to Read the Special Markings on a Tape Measure
Why are some numbers on the tape measure red?
When reading a tape measure made especially for contractors, you may notice some special markings. Every 16 inches (16, 32, 48…), there is a bold, red or colored marker that is different from the others. These mark the standard 16" stud locations.
What do black diamonds mean on a tape measure?
Then there are the mysterious floating black diamonds. These measures are not as accurate as stud markings. These are 19 3/16, 38 3/8, 57 9/16 and 76 3/4. They are used to set up trusses. Specifically, they were used to set up six trusses over an 8-foot span (the length of a single piece of plywood). The 0 mark and the 8 foot mark form two marks with four black diamonds in between.
While we didn't go into detail about these, here are some other special tape measure markers we've seen:
- Conduit Curved Guide
- Blueprint Guide
- yard marker
- 1/32 inch mark
Will the hook affect tape measure accuracy?
The hook slides back and forth on the front of the blade, which is on purpose. It slides the exact width of the hook so you get accurate measurements whether you're pushing it against the material or pulling it from the side.
Have any questions about reading a tape measure? Drop them in the comments below and we'll have an answer for you!
Like the tape measure we used in the photo? This is the 25 foot Milwaukee Stud and we highly recommend it!