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Metric Converter

For all of you old buggers, here you can do conversions from imperial to metric to (inches to mm)

Imperial to Metric Conversion Formula

Example

Imperial Fraction 3/16 is 4.68mm Metric

Conversion Formula is

25mm divided by 16 x 3 equals 4.68mm

And if a measurement has full inches before the Imperial Fraction you must add 25.54mm for each inch - 1 Inch is 25.54mm

Example

2 and 3/16 inches converts as below:

2 inches which is 51.08mm and 3/16 inches which is 4.68mm

Conversion into Metric is 55.76mm

Or use the tables below

Fractional and Decimal Inch and Metric Conversion Tables
Fractional Inches to Decimal Inches to
Approximate Millimeters to Practical Millimeters

Decimal inches multiplied by 25.4 = approximate mm. N.B. When specifying metric sheet or trim sizes, fractional approximate mm measurements must be rounded off to the nearest whole number; i.e., 50.8 mm is not a practical measurement; it should be rounded up to 51 mm, and 0.5 mm is always rounded down.
Fractional Inch Decimal
Inch
Approximate Millimeters Practical Millimeters
1/16 0.0625 1.5875 2
1/8 0.1250 3.1750 3
3/16 0.1875 4.7625 5
1/4 0.2500 6.3500 6
5/16 0.3125 7.9375 8
3/8 0.3750 9.5250 10
7/16 0.4375 11.1125 11
1/2 0.5000 12.7000 13
9/16 0.5625 14.2875 14
5/8 0.6250 15.8750 16
11/16 0.6875 17.4625 17
3/4 0.7500 19.0500 19
13/16 0.8125 20.6375 21
7/8 0.8750 22.2250 22
15/16 0.9375 23.8125 24
1.0 25.4 25

 

Millimeters to Decimal Inches to Approximate Fractional Inches to Practical Fractional Inches

Millimeters divided by 25.4 = decimal inches. N.B. Fractional
practical inches have been rounded to the nearest 1/16 inch, whichmay not always be a practical measurement when specifying sheet or trim sizes in inches.

"<" = less than; ">" = greater than

Millimeters Decimal Inch Approximate Fractional Inch Practical Fractional Inch
1 0.03937 <3/64 0
2 0.07874 >5/64 1/16
3 0.11811 >7/64 1/8
4 0.15748 >5/32 3/16
5 0.19685 <13/64 3/16
6 0.23622 >15/64 1/4
7 0.27559 <9/32 1/4
8 0.31496 >5/16 5/16
9 0.35433 >11/32 3/8
10 0.39370 <13/32 3/8
11 0.43307 >27/64 7/16
12 0.47244 >15/32 1/2
13 0.51181 <33/64 1/2
14 0.55118 >35/64 9/16
15 0.59055 <19/32 9/16
16 0.62992 <41/64 5/8
17 0.66929 >21/32 11/16
18 0.70866 <23/32 11/16
19 0.74803 >47/64 3/4
20 0.78740 >25/32 13/16
21 0.82677 <53/64 13/16
22 0.86614 >55/64 7/8
23 0.90551 <29/32 7/8
24 0.94488 <61/64 15/16
25 0.98425 >31/32 1