Most people write measurements using the metric system, so it’s not a surprise many woodworking references are based on it. The only problem is it makes newbies confused when converting dimensions from feet and inches symbols.
Here’s a brief discussion curated by our experts to help save time and prevent you from making wrong measurements on your next project.
What’s the Feet Symbol?
The symbol for feet often comes up when you need to buy lumber, shingles, or pipe. You can write feet in two ways: either in its abbreviated form “ft” or its marking in the form of a single apostrophe (‘).
Typically, the measurement dimensions in a lumber yard are often written symbols for feet and inches. For example, a wooden board with the exact size of 2 in. x 6 in. x 12 ft. reads as a material that’s 2 inches thick, 6 inches wide, and 12 feet long.
Remember that the symbols “ft” and single apostrophe (‘) denote feet not only in their plural form but also in their singular variation. This condition means that one foot and five feet can use the “ft” abbreviation.
Are Lumber Board Length Measurements in Feet Precise?
If you’ve been a woodworker long enough, you’d know wood materials don’t often align with their listed dimensions. These issues often come up when dealing with the lumber’s width and length.
For example, a board with listed dimensions of two inches thick and six inches wide doesn’t have these exact specifications if you get it measured. At best, this wood material’s actual size is 1 ½ inches by 5 ½ inches because it has gone through manufacturing.
The good news is these procedures often don’t affect the lengths of the boards you’ll get from your nearest lumber yard. If you bought a piece of wood that’s eight feet in length, the measurements on its label wouldn’t be different from its actual size.
Even if the material is labeled 8 inches tall instead of symbols for feet, it doesn’t indicate that the board has an inaccurate length measurement.
Centimeters Per Foot
Since most people use the metric system, you’ll encounter many materials labeled in centimeters (cm) and meters (m). It may sound intimidating, but the metric system is easy to understand because it’s measured in ten units.
The confusion often comes from converting centimeters to feet, a unit from the imperial system.
To convert feet, the best advice our woodworkers can give is to break them into inches. By this, we mean taking note of the equivalency of twelve inches to one foot.
With one inch equivalent to 2.54 centimeters, the next step you ought to do is convert feet into inch measurements. Try to multiply 2.54 by 12, and you’ll get the answer of 30.48 centimeters. If you round that off, it shows that a single foot equals 30 centimeters.
Meanwhile, one meter has an equivalency of around three feet. You’ll notice that one yard and meter include similar measurements.
How to Convert Feet to Centimeters
Now that you know how to convert ft to cm, it’s time to learn how to do it the other way around. For this method, you must write inches instead of feet.
For example, you want to convert five feet into centimeters. You can do this conversion by multiplying the feet measurements by 12, which leads to 5 times 12 equals sixty inches.
After that, you must multiply sixty inches by 2.54 to get the equivalent centimeters. From there, the answer will be 243.8 cm.
What’s the Inches Symbol?
It’s easy to confuse feet and inches because they have similar symbols. As you know, the symbol for feet is written in a single apostrophe (‘). Meanwhile, the symbol for inches goes in the form of a double apostrophe (“).
Take height measurements like 5’ 10” as an example, where the number with single quotation marks after is read as 5 feet, and the number with the double apostrophe is ten inches.
So if you start second-guessing what the symbol for inches is, don’t forget that it’s the one with double quotation marks.
How Inches is Abbreviated
Now that we discussed the foot and inch symbols, it’s time to tackle the abbreviations for this unit of measurement.
Instead of an inch symbol, you can write one inch with “in” as its shortened term. Sometimes, you’ll encounter people adding an extra (“ins”) at the end of the word. Here’s an example to help you understand how the inches abbreviation works:
If you went to a wood shop and saw boards marked 4 ft. and 5 in., you should know that it reads as four feet and five inches long.
Centimeters Per Inch
Since this unit doesn’t belong to the metric or international system, converting inches can be challenging for some people. When the measurement of one material does not match the other, it can compare to communicating with different languages.
For example, you’re working on installing a sink with measurements written in centimeters or meters. The problem will arise if the kitchen top has specifications in inches.
Fortunately, you can convert inches to centimeters easily. All you need to do is remember that an inch is equivalent to 2.54 centimeters.
Let’s formulate an example below to help you convert inches better:
First, let’s say you have a pipe that’s 15 inches thick and want to convert this specification into cm. Unlike converting feet, this method only requires you to multiply that 15 inches by 2.54. It will lead you to the answer that 15 inches have the same value as 38.1 centimeters.
Prime Mark History
While it’s true that prime marks are used in mathematics, it’s also a term used in feet and inches to describe the written order of height and length.
Feet measurements are typically considered the prime symbol because they’re always mentioned first. Because of this, they come with a single prime mark.
And since inches come in the second order, they’re represented with double prime symbols. Don’t forget that smaller prime marks often take up less space, making them easier to use and read.
Single prime and double prime marks are common, but you’ll encounter triple prime marks in ligne indications.
How It’s Written
Many people confuse prime marks with quotation marks or apostrophes. However, double or single prime marks are written on a straight left edge, slightly slanted to the right.
Since modern keyboard doesn’t have dedicated options for prime symbols, it’s only natural that these marks are typed or written in quotations and apostrophes.
Use of Prime Mark
Besides measurements, prime marks also represent angles. In arcminutes, a single prime mark denotes 1/60 of a degree. Meanwhile, double-prime refers to arcseconds or 1/60 of an arcminute.
You can also use prime marks as symbols for time. Double prime often indicates seconds, whereas single prime is the minute symbol.
Why Do We Use Inches and Feet for Units of Measurement?
Unlike other measurements shortened from a word, you can write feet and inches in symbol forms. The reality that the symbol for feet is an apostrophe and inches come with quotation marks makes these units easy alternatives that save time and space.
Why Should You Understand the Symbols?
Not everyone is an industry expert, but most manufacturers, in-store or online, don’t bother putting the whole spelling of measurements in their products. Generally, you’ll encounter specifications with written symbols.
And given that feet and inches have similar symbols, it’s only natural that you get confused between them. Here’s another example to shed light on this:
You’re instructed to buy material with 2 x 8 x 16’ specifications. What does this mean? The measurement refers to a workpiece with sizes around 2 inches thick, 8 inches wide, and sixteen feet long.
Once you understand this method, you won’t have difficulties differentiating feet and inches from one another.
Symbols vs. Abbreviation
The truth is symbols are more widely used than abbreviations. Written below are some arguments that prove this conclusion:
As a woodworker, our experts can assure you that this craft consumes extensive time. Writing marks takes less time than abbreviations if your project involves taking measures. By using these alternatives, you can get back to work faster.
If we talk in the simple logic of writing, a mark consumes less space than an abbreviation. This logic also applies when working on a blueprint for your project because it would prompt you to include material specifications.
While there’s no harm in writing feet and inches in their complete spelling, these words can crowd the blueprint and lead to confusion.
No matter what language you’re using, symbols don’t change their uses or meanings. Meanwhile, it’s crucial to note that abbreviations can have different definitions in other languages.
How are Lumber Board Dimensions Measured?
Most rough-sawn materials are sold in quarters. If you don’t know what that means, it simply refers to the thickness of the lumber measured in quarter increments. You’ll see wood pieces labeled in “4/4,” which means they’re cut in 4 quarters or an inch thick.
These measuring methods are often used in DIY crafting and construction. You’ll also encounter these dimensions in wood shops, selling lumber and other wooden materials in inches.
Board Foot Sizing
You should understand how Board-Feet sizing works if you’re buying rough-sawn lumber in bulk. It’s sold in 144 cubic feet measurements, so expect it to be cheaper.
Should I Purchase Lumber With Exact Measurements?
It’s nearly impossible to buy wooden boards with accurate measurements, especially in standard sizes like 2×4 or 2×6. If you want materials with exact sizes, our best advice is to buy specialty wood boards.
These options are often available in local hardware stores, but remember that they can be more expensive. Nevertheless, these are the selections you can be sure of accuracy.
Is the Width of Lumber in Inches Accurate?
No matter what unit the materials are measured in, the reality is not every size on their labels is accurate. While length specs are often precise, we can’t say the same for thickness and width after it has gone through the manufacturing process.
How should you write height in the form of feet and inches?
You can write height in feet by its abbreviation (ft) or its prime mark (‘). Meanwhile, height in inches is written in its (in) or (ins) abbreviation. You can also refer to it in its double prime sign (“).
How does the imperial system differ from the metric system?
The metric system comprises divisible figures from numeric progressions of millimeters, centimeters, and meters. On the other hand, the imperial method follows a pattern of inches, feet, and yards.
How many inches are in one foot?
There are 12 inches in every foot, which you can say is a bit longer than a roman foot. You may not know, but it’s an old quantification of 11.64 inches.
Some woodworking errors are often made when newbies fail to determine the difference between the feet and inches symbols. After learning how these methods work, we don’t doubt they’ll elevate your craft’s accuracy.
This know-how can also save you money and time in the long run since you’ll buy the right measurement material.
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