How to Read a Tape Measure?

The tape measure is the world’s most commonly used measuring tool, accompanying millions of tradesmen and contractors to work every single day.

Whilst the seasoned professionals amongst you will no doubt be fully aware how to read the various markings on your tape, there will be amateurs, enthusiasts or those just starting off in their careers who aren’t yet so knowledgeable.

We regularly get asked the question “how do you read a tape measure”. In response to our customers, therefore, we’ve put together this simple guide that explains just that!

What is a Tape Measure?

A tape measure or measuring tape is a flexible ruler used to measure length or distance. It consists of a ribbon of cloth, plastic, fiberglass, or metal strip with linear measurement markings. It is a common measuring tool.

Its design allows for a measure of great length to be easily carried in a pocket or toolkit and permits one to measure around curves or corners.

A tape measure is a portable measurement device used to quantify the size of an object or the distance between objects. The tape is marked along the tape edge in inches and fractional inches, typically in quarter-, eight-, and sixteenth-inch increments. Some tape measures are marked in millimeters, centimeters, and meters on one edge.

The most common tape measures 12 feet, 25 feet, or 100 feet in length. A 12-foot tape measure is the handiest for consumers.

The 25-foot length is called a builder’s tape and is marked in feet and at 16-inch increments to make measuring the standard distance between wall studs easier.

The 100-foot tape, usually of reinforced cloth, is useful for determining property boundaries and other exterior measurements.

Types of Tape Measures

Unlike rulers, tape measures are made of flexible cloth, metal, or fiberglass ribbon. They come in varying lengths and feature measurement markings. There are four basic types of tape measures: case, long or open-reel tapes, diameter tape (D-tape), and sewing tapes.

1. Cased Tape Measures

This classic 25-foot measuring tape can be used by home DIYers and contractors. They are retractable, featuring a spring mechanism to recoil the blade.

Its compact and portable design makes this tape measure type a must-have tool for a variety of building and craft purposes and the best tape measure for woodworkers.

2. Open Reel Tape Measure

Generally used by surveyors, an open reel measuring tape has no spring mechanism to coil the blade. It uses a hand-crank method to roll up the blade.

It’s a long tape measure that is best for measuring far distances. For large areas or distances, most professionals will opt for a measuring wheel.

3. Diameter Tape Measure

Similar to a case tape measure, a diameter tape measure (D-tapes) features an ultra-flexible blade that can easily wrap around pipes and poles.

It provides an accurate measurement using pi (the ratio of a circle’s circumference to its diameter) to calculate the circumference and diameter of a cylindrical object.

4. Sewing Tape Measure

Also known as a tailor’s tape, sewing tapes are ultra-flexible and mold easily to the body. They are used for accurate measurements for clothing design and alterations.

They range in length from 60 to 120 inches. They also have both imperial and metric measurement markings.

Anatomy of a Tape Measure

Learning how to read a tape measure begins with understanding its different parts.

The case is the square-shaped housing for the tape. It is usually plastic or metal and about 3 inches in length.
The hook is a bent piece of metal that hooks over the edge of a board or counter. It aids in extending the tape from the case and holding the tape in place for measuring.
The hook slot is the hole at the end of the tape. It allows you to latch onto an anchor point such as a protruding nail or screw head.
The actual tape or blade is usually yellow or white. It’s the extendable and retractable length of the tool. Most often the blade is made of metal coated in plastic.
The thumb lock is a button on the case. When pressed, the thumb lock will hold the extended tape measure to a needed length. Releasing the thumb lock will allow the tape to retract into the case.
The belt clip is the fastener on the side of the case. It allows you to hook your tape measure conveniently onto a belt, tool belt or pocket.

Basics Of Tape Measure

Above you’ll see a picture of a metric/imperial pocket tape measure. The measurements towards the bottom of the image are metric. In other words they’re in centimetres and milimetres.

There are 10mm in each centimetre (shown by the ten spaces between each cm) and 100cm in each metre. Whilst the centimetres are clearly numbered, to make the blade easier to read the millimetres are not numbered.

Also, whilst a few tapes show ‘1m’ to display the 1 metre mark, the majority will show ‘100cm’.

When referring to the diagram above you’ll see a series of large numbers marked 1, 2, 3, and 4. These numbers sit next to long vertical marks which represent whole inches. Put simply 1 = 1″, 2 = 2″, and so on.

Between those numbers are a series of shorter marks which represent fractions of an inch. The mark directly in the middle of the inch denotes a measurment of 1/2″ whilst the markings either side of it represent measurements of 1/4″ and 3/4″ respectively.

Even smaller marks then denote 1/8ths and 1/16ths (marked in red) of an inch.

A 16ft tape measure, for example, will have sixteen one-foot marks along its length and 192 one-inch marks (12 inches per foot). Each inch will then have eight 1/8th of an inch and sixteen 1/16th of an inch marks.

1 foot = 12 inches
1 inch = 16 x 1/16th of an inch, 8 x 1/8th of an inch, 4 x 1/4 of an inch or 2 x 1/2 of an inch.

How to Read a Tape Measure

Find/read the markings. On a standard tape measure, the biggest marking is the inch mark (which generally has the biggest number, if it has them).
As the increments decrease, so does the length of the mark. For example, ½” has a bigger mark than ¼” which has a bigger mark than ⅛”, and so on.
Read 1 inch. The space from the largest mark to another is 1 inch.
Read one-half inch. Same principle as reading one inch, only this time the space between the second-biggest mark and the biggest is read. You can think of a half-inch mark as halfway between a full inch.
The remaining markings follow a similar pattern. ¼” is half of ½”. ⅛” is half of ¼”. Most tape measure markings go as small as 1⁄16;”. This tape divides one more time, down to 1⁄32″.

How to Measure Using a Tape Measure

Measure a length. Place the end of the measure at one end of the object or space to be measured. When the length stops, read off the tape measure.
Find the length. To determine the length, you must add up the lengths between inches. For example, the following image has a measurement that extends beyond the distance between two-inch marks (i.e., a full inch). To find the length, add the length of the inch (1) to the distance between the second- and third-inch marks. In this case you would add 1 inch + 1/4 inch to get 1¼ inch or “one and a half inches”.
If the length is less than 1 inch, simply read the length from the tape measure. increments of an inch are not labeled, determine the increment of the mark and add the appropriate fractions.
As an example, the image below shows a length ranging from the inch mark to an unmarked mark. We know it’s over 3/4 inch and under a full inch. The mark is halfway between 3/4 (6/8) and 7/8. Therefore, the mark is half of 1/8 or 1/16. Knowing this, you simply add up the known fractions to find the length. Convert 3/4 to 12/16 for common denominators and add 12/16 + 1/16 to get 13/16 – that’s your length.

How to Read a Tape Measure in Inches

Standard or SAE tape measures clearly show feet, inches, and fractions of inches. The measurements on a tape measure are generally 16 marks to the inch. This means you can measure up to 1/16 of an inch. Some tapes measure from 32 to 64 marks to the inch. Laser distance measurers can often measure accurately within 1/16 inch.

When reading a tape measure, find the closest whole inch to the end point. Then examine leftover indicator lines to see what fractions of an inch remain. Add those to the whole inches for your total measurement.
To read an inch, look for the large numbers. That number is usually in bold, black type. It’s easy to see and refers to the longest of the markings along the edge. The number of lines between inch marks indicate how precise you can get with your tool.
To read 1/2-inch measurements, locate the second-longest mark between the longer inch marks. For 1/4-inch marks, look halfway between the 1/2-inch marks. You can read smaller fractions of an inch the same way. Most tapes will label the fractions to make finding them easier.

How to Read a Tape Measure in Millimeters

Metric tape measures feature 10 marks to the centimeter. The smallest marks on a tape indicate one millimeter or 1/10th of a centimeter. The large, bold markings on a metric tape measure indicate centimeters. The long mark in the center indicates a half-centimeter.

To read a metric measuring tape, find the nearest whole centimeter to the end point. Examine the remaining indicator lines to see how many millimeters are left over.
Add those to the whole centimeters, using a decimal. For example, say you measure 20 whole centimeters and there are 6-millimeter marks left over. Your total measurement will be 20.6 centimeters.

Special Notes for How to Read Measuring Tape

The typical length between studs in a wall is 16 inches on center. This is marked in red on many tape measures.
Many tape measures will have 1 foot marks every 12 inches. This eliminates the need to convert inches to feet yourself. Some have special markings every 3 feet as well.
Tape measures often use small, black diamond or triangle shapes called black truss marks. They indicate truss layouts of every 19 3/16 inches. This spacing is often used by some engineered joist manufacturers. There are 5 of these marks for every 8 feet.

Tape Measure Tips

A properly functioning hook will move slightly. It is designed to slide based on the thickness of the metal, usually about 1/16-inch. This allows the tape to give an accurate inside and outside measurement.
Standard tape measures usually go from 15 to 50 feet. Long tape measures come in greater lengths of 100 feet or more. They are often made of flat steel or fiberglass and retract with a hand crank. Self-retracting tape measures are flexible and can be bent to measure into tight spaces or around corners.
Use a screw or nail as an anchor point to fix the end of your tape measure in place.
To draw a perfect circle, anchor the tape measure’s hook slot onto an anchor point. Engage the thumb lock. Hold a pencil or other writing utensil down flush with your tape measure. Turn it in a circle around the anchor point.
Be careful when retracting a tape measure. Allowing it to snap back can damage the tape and possibly give you a cut. Instead, retract the tape back in slowly.
If the hook on your tape measure is bent or damaged, you’ll get inaccurate measurements. A bent hook can often be adjusted with two pair of pliers. Or tap it with a hammer against a hard surface.
If you’re using multiple tapes on the same job, calibrate them to any one of several good rulers and yardsticks available. Tapes can be brought into agreement by slightly bending the hooks until measurements match.

Reading a tape measure is a skill you can easily master. Using this small, sturdy hand tool can improve the accuracy of your project measurements. Learning how to use a tape measure properly means to always “measure twice, cut once.” You can use a standard tape measure or opt for a metric one.