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If you have inches but need millimeters:

In ascending order of size…
1/16 inch equals almost 2mm

1/8 inch = little more than 3mm

1/4 inch = little more than 6mm

3/8 inch = nearly ten millimeters

1/2 inch equals almost 13mm

16mm Equals 5/8 inch

19mm Equals 3/4 inch

7/8 inch = slightly more than 22mm

1 inch is equal to 25.4mm

If you have millimeters and need an inch conversion:

1mm is a little more than 1/32 inch.

2mm = little more than 1/16 inch

3mm is about 1/8 inch.

4mm = 5/32 inch (= little more than 1/8 inch).

5mm = little more than 3/16 inch

6mm is almost 1/4 inch.

7mm = almost 9/32 inch (= somewhat more than 1/4 inch)

8mm is equal to 5/16 inch.

9mm is almost 3/8 inch.

10mm = little more than 3/8 inch

11mm is about 7/16 inch.

12mm is about 15/32 inch (almost 1/2 inch).

13mm is somewhat more than 1/2 inch.

14mm is almost 9/16 inch.

15mm is about 19/32 inches.

16mm is equal to 5/8 inch.

17mm is about 11/16 inch.

18mm = little more than 11/16 inch

19mm is equal to 3/4 inch.

20mm is equal to 25/32 inches.

21mm = little more than 13/16 inch

22mm is almost 7/8 inch.

23mm is equal to 29/32 inch.

24mm = little more than 15/16 inch

25mm is almost an inch.

Conversions in the Calculator

If you have inches and wish to know the millimeter equivalent:

Convert any inch fractions to decimals in step one.

1/4 inch equals 1 divided by 4 equals 0.25 inches.

For instance, 1/16 inch equals 1 divided by 16 is 0.0625 inches.

For values more than an inch, you need first convert the fractional portion and then add the whole inch portion:

For instance, 2-1/4 inch is one divided by four, plus two equals 2.25 inches.

For instance, 1-5/8 inch is 5 divided by 8, plus 1 equals 1.625 inches.

Multiply the decimal value by 25.4

The entire steps for each of the above instances are as follows:

1/4 inch = 1 divided by 4, multiplied by 25.4 equals 6.35mm (6mm)

1/16 inch = 1 divided by 16, multiplied by 25.4 equals 1.5875 (1.6mm)

2-1/4 inch equals 1 divided by 4, plus 2, multiplied by 25.4 equals 57.15. (57mm)

1-5/8 inch equals 5 divided by 8, plus 1, multiplied by 25.4 equals 41.275. (41mm)

If you have millimeters (or centimeters) and desire inches, follow these steps:

Divide your millimeter measurement by 25.4

(or double your centimeter measurement by 2.54)

2mm divided by 25.4 equals.07874 inches in Example 1.

6mm divided by 25.4 equals.2362 inches in Example 2.

30mm divided by 25.4 is 1.1811 inches in Example 3.

4cm divided by 2.54 is 1.5748 inches

If you’re calculating the number of 6mm beads required for a 20″ necklace, you may directly use this decimal amount. As seen in Example 2, a 6mm bead equals.2362 inches.

Therefore, twenty lengths (per necklace) divided by.2362 inches (per bead) equals 84.67 beads per necklace.

Given that you’ll probably need some room for bead tips and a clasp, I’d round down to 80 beads. Chart indicating the number of beads per strand

If, on the other hand, you want fractions of an inch (1/16, 1/4, 1/2), try this:

The second step is to convert your decimal to a usable fraction:

I tend to round my measurements to the closest 1/16 of an inch. Multiply your decimal by 16 to get the closest 1/16 of an inch. The result is the number of 1/16ths of an inch that you have.

Using the same numbers as in Step 1:

.07874 multiplied by 16 is 1.26, which rounds to 1, or around 1/16 inch.

.2362 multiplied by 16 is 3.779, which rounds to 4, or about 4/16. 4/16 equals 1/4 inch.

For quantities more than an inch, it is best to exclude the whole inches and reintroduce them after converting the section after the decimal point:

1.1811 By omitting the 1, you get. 1811 multiplied by 16 is 2.9, which rounds to 3, or approximately 3/16 inch… don’t forget to put the 1 back in, which makes this 1-3/16 inch.

1.5748 By omitting the 1, you get. 5748 multiplied by 16 is 9.1968, which rounds to 9, or about 9/16 inch… don’t forget to put the 1 back in, which makes this really 1-9/16 inch.

I do not advocate rounding to bigger fractions, such as 1/4 or even 1/8 inch, for jewelry reasons. If you are not producing jewelry or your requirements are not precise, round to a greater fraction, such as 1/4. Simply replace all 16’s in Step 2’s examples with 4’s to round to the closest 1/4 of an inch.

Using the same values as in step 1, and as in step 2, you would get…

.07874 multiplied by four equals.315, which rounds to zero, yielding a value of 0/4 of an inch (not a very useful value!).

.2362 multiplied by four equals.9448, which rounds to one, resulting in a quarter of an inch (which happens to be accurate)

Numerous Numeric Values for Conversions

Converting…

Convert inches to millimeters by multiplying by 254.

multiply by 2.54 to convert inches to centimeters

Convert millimeters to inches by multiplying by 25.4

Convert centimeters to inches by multiplying by 2.54.

Convert meters to feet by multiplying by 3.28

To convert feet to meters, multiply by 3.28.

Convert millimeters to centimeters by multiplying by ten

Convert centimeters to meters by multiplying by 100