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 "<" = 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 |