Sometimes you need to switch between millimeters (mm) and inches (in). Millimeters and inches are used to measure length, but one is metric and the other is part of the US customary/imperial system. This means that converting between them is important in many areas of life, including engineering, manufacturing, and even your own DIY projects.
This article will show you exactly how to convert 16.5 mm to inches. We’ll cover the formula, some examples, and useful tools you can use to make conversions faster.
You can use a formula, conversion charts, or online calculators to switch between these units.
Understanding millimeters and inches
To convert millimeters (mm) to inches, it helps to understand what these units of measurement represent.
What is a millimeter?
A millimeter is a unit of length in the metric system. There are 1,000 millimeters in a meter.
To give you an idea of how small a millimeter is, the thickness of a U.S. dime is 1.35 mm.
What is an inch?
An inch is a unit of length in the U.S. customary and imperial systems of measurement. There are 12 inches in a foot and 36 inches in a yard.
One inch equals 2.54 centimeters.
How to convert millimeters to inches
The formula you need to convert millimeters to inches is: inches = millimeters ÷ 25.4. It’s important to use this formula exactly to get an accurate conversion.
The conversion factor “25.4” comes from the official definition of an inch. One inch is defined as exactly 25.4 millimeters.
So, to convert 16.5 mm to inches, you’d calculate: 16.5 mm ÷ 25.4 = 0.6496 inches. For most practical purposes, we can round that to 0.65 inches.
Therefore, 16.5 mm is about 0.65 inches.
Converting 16.5 mm to fractional inches
In some fields, it’s more common to use fractional inches than decimal inches. Construction, woodworking, and other areas that require highly precise measurements often rely on fractional inches.
Here’s how to convert millimeters to fractional inches:
- Convert millimeters to decimal inches, as detailed above.
- Decide how precise you want to be (e.g., 1/16, 1/32, or 1/64 of an inch).
- Multiply the decimal part of your inch measurement by the denominator of your desired fraction.
- Round the result to the nearest whole number.
- Write the result as a fraction.
Example: Converting 0.6496 inches to the nearest 1/16th of an inch
- Multiply 0.6496 by 16: 0.6496 16 = 10.3936
- Round to the nearest whole number: 10
So, 16.5 mm is about 10/16 of an inch, which you can simplify to 5/8 of an inch.
Practical Applications and Tools for Conversion
Converting millimeters to inches comes in handy in all sorts of situations. If you’re working on a DIY project, putting together engineering designs, or even picking the right size drill bit, you may need to switch between metric and imperial measurements.
Conversion charts and tables can be a quick and easy way to look up common millimeter-to-inch conversions. You can find these charts online with a quick search.
Online conversion calculators are super convenient, too. Just plug in the millimeter measurement, and you’ll instantly get the equivalent in inches. Many of these calculators are available as mobile apps, so you can convert on the go.
Of course, you can also use a good old-fashioned ruler or tape measure for physical measurements. Just make sure your measuring tools are accurate to get the most precise conversions.
The Bottom Line
In this article, we’ve covered the formula for converting millimeters to inches, discussed equivalent fractional inches, and pointed you to some handy tools that make the conversion easy.
Understanding how millimeters and inches relate to each other is important in design, engineering, manufacturing, and many other fields.
So, whether you use the formula, the conversion charts, or one of the calculators, we hope you’ll come back to this article anytime you need to convert millimeters to inches.