| Because millimeters are very small, they are perfect for measuring jewelry parts. For example, the gluing surfaces on most of ourflat pad posts are 3mm, 4mm, 6mm, 8mm, and 10mm. If those were converted to inches, they would be (in order) approximately 1/8 inch, 5/32 inch, 1/4 inch, 5/16 inch, and 3/8 inch. Even if you've always hated the metric system, that row of millimeter sizes is clearer than that row of inch fractions: it's obvious that 4mm is larger then 3mm ... but is 1/8" larger or smaller then 5/32"? In case you've never gotten along with millimeters, or in case you need to do some conversions and never got along with algebra, this page contains easy conversions back and forth between inches and millimeters.
Sections on this page: | If you have inches, and want to know how many millimeters:- Step one: Convert any inch fractions to decimals.
Example: 1/4 inch = 1 divided by 4 = 0.25 inch
Example: 1/16 inch = 1 divided by 16 = 0.0625 inch- For amounts over an inch, you want to first convert the fractional part, then add the whole inches part:
Example: 2-1/4 inch = 1 divided by 4, then plus 2 = 2.25 inch
Example: 1-5/8 inch = 5 divided by 8, then plus 1 = 1.625 inch
- Step two:Multiply that decimal by 25.4
For each of the above examples, the complete steps would be:
1/4 inch = 1 divided by 4, x 25.4 = 6.35mm (6mm)
1/16 inch = 1 divided by 16, x 25.4 = 1.5875 (1.6mm)
2-1/4 inch = 1 divided by 4, plus 2, x 25.4 = 57.15 (57mm)
1-5/8 inch = 5 divided by 8, plus 1, x 25.4 = 41.275 (41mm)
If you have millimeters (or centimeters), and you want inches:- Step one: Divide your millimeter amount by 25.4
(or divide your centimeter amount by 2.54)
Example 1: 2mm divided by 25.4 = .07874 inches
Example 2: 6mm divided by 25.4 = .2362 inches
Example 3: 30mm divided by 25.4 = 1.1811 inches
Example 4: 4cm divided by 2.54 = 1.5748 inches
If you are trying to figure out how many 6mm beads you need for a 20" necklace, you can use this decimal value directly. From Example 2 above, you know that a 6mm bead = .2362 inches.
So, 20 inches (per necklace) divided by .2362 inches (per bead) = 84.67 beads per necklace.
Since you probably need to reserve a bit of space for your bead tips and a clasp, I would round down to 80 beads. Number of beads per strand chartIf, however, you want fractions of an inch (1/16, 1/4, 1/2), rather than a decimal, try this: - Step two: Converting your decimal to a useable fraction:
I prefer to round to the nearest 1/16 of an inch. To round to the nearest 1/16 of an inch, multiply your decimal by 16. The resulting number is how many 1/16's of an inch you have.Using the numbers from Step 1 above:
.07874 times 16 = 1.26, which rounds to 1, so about 1/16 inch.
.2362 times 16 = 3.779, which rounds to 4, so about 4/16. 4/16 = 1/4 inch - For amounts over an inch, it is easiest to remove the whole inches, and add them back in after you convert the portion after the decimal point:
1.1811 Removing the 1 gives you .1811 times 16 = 2.9, which rounds to 3, so about 3/16 inch... don't forget to add the 1 back on, so this is really 1-3/16 inch.
1.5748 Removing the 1 gives you .5748 times 16 = 9.1968, which rounds to 9, so about 9/16 inch... don't forget to add the 1 back on, so this is really 1-9/16 inch.
For jewelry purposes, I don't recommend rounding to larger fractions, such as 1/4, or even 1/8 inch. If you are not making jewelry, or your needs are not very exact, then you can round to a larger fraction such as 1/4. To round to the nearest 1/4 of an inch, simply replace all the 16's in Step 2's examples with 4's.
Using the numbers from step 1, that I also used in step 2, you would get...
.07874 times 4 = .315, which rounds to 0, so you get 0/4 of an inch (not a very useful number!)
.2362 times 4 = .9448, which rounds to 1, so you get 1/4 of an inch (which happens to be accurate) | To Convert...- inches to millimeters, multiply by 25.4
- inches to centimeters, multiply by 2.54
- millimeters to inches, divide by 25.4
- centimeters to inches, divide by 2.54
- meters to feet, multiply by 3.28
- feet to meters, divide by 3.28
- millimeters to centimeters, divide by 10
- centimeters to meters, divide by 100
| FAQs
Common items that can be used to show tumor size in mm include: a sharp pencil point (1 mm), a new crayon point (2 mm), a pencil-top eraser (5 mm), a pea (10 mm), a peanut (20 mm), and a lime (50 mm).
What is an example of a millimeter in real life? ›
One millimeter equals approximately 0.039 inches. What are some real-life objects having a 1 mm dimension? Some examples of objects having about 1 millimeter length areA sharp pencil point and the tip of a sewing needle are approximately 1 mm in length.
How big is 1 mm on a ruler? ›
Even a very inexpensive, imprecise ruler will usually make the smallest division a 1/6th of an inch. If there is metric measure in centimeters on the other edge of that same ruler, the smallest division will commonly be a millimeter (mm). The millimeter is just slightly smaller than a 1/6 of an inch.
How big around is a millimeter? ›
1 millimeter is equal to 0.03937 inches, or 5/127 of an inch. There are 25.4 millimeters in 1 inch.
How big is a mm actual size? ›
Since an inch is officially defined as exactly 25.4 millimetres, a millimetre is equal to exactly 5⁄127 (≈ 0.03937) of an inch.
What is 1 mm size object? ›
1 mm: The tip of a sharpened pencil or the width of a standard staple. 2. 1 cm: The width of a small paperclip or the height of a LEGO brick.
Where is 1 mm on a tape measure? ›
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.
What does 5 mm look like? ›
5 mm is a very small length measurement, roughly equivalent to 0.2 inches. It is about the thickness of a pencil lead or the width of a small paperclip. It is roughly the size of the end of a pinky finger. It is small enough that it can be difficult to see with the naked eye.
What is 1 inch equal to in mm? ›
In summary, 1 inch is equal to 25.4 millimeters.
How do I measure millimeters? ›
If you have a metric ruler, note that the numbered lines represent centimeters and the unmarked lines represent millimeters. One centimeter is equal to 10 millimeters. Put the zero end of the ruler at the starting edge and count the unnumbered lines after the last numbered mark.
A millimeter (mm) is 1/1000th of a meter. A dime is approximately 1 mm thick. Grains of sand range from 0.1 mm to 2 mm in size.
What is the smallest part of a millimeter? ›
One millimeter is equal to 1000 micrometers. One millimeter is equal to 1 000 000 nanometers. One inch is equal to 25.4 millimeters.
What is roughly 1 mm? ›
One millimeter is approximately equal to 0.0394 inches. There are 25.4 millimeters in an inch. To convert millimeters into inches, divide the length in millimeters by 25.4.
How thin is 1 mm? ›
1mm = just over 1/32 inch. 2mm = just over 1/16 inch. 3mm = almost 1/8 inch. 4mm = 5/32 inch (= a bit over 1/8 inch)
What can measure 1mm? ›
The tool that can measure the smallest length is therefore the most accurate tool for measuring length. Rulers and tape measures both measure minimum lengths of 1 mm, while vernier calipers and micrometer can measure lengths of less than 1 mm. Vernier calipers can measure a minimum length of 0.1 mm.
