How to Convert Fractional Inches to Metric

Converting fractional inches to metric units requires a calculator.

Converting measurements from the U.S. system into the metric system is tricky enough when you are using whole numbers. You must be able to decide what metric measurement you wish to convert the units into -- for example, you probably will not wish to convert inches into kilometers -- then do the math necessary to make the conversion. This process requires yet another step when you must also deal with fractions; converting 1/4 inch into millimeters is much simpler when you address it as 0.25 inch instead.

Things You'll Need

• Calculator

Instructions

1. Divide the top number in your fractional inches by the bottom number. If there are any whole inches in your number, you can leave them out for the moment. If, for example, you wish to convert 5 3/8 inches to metric, divide 3 by 8 for a total of 0.375.

2. Add the converted fractions to the whole inches from your original number. In our example, you would add 0.375 to 5 for a total of 5.375 inches. This is the equivalent of 5 3/8 inches.

3. Multiply your number by 25.4 to convert it to millimeters, 2.54 to convert it to centimeters, 0.254 to convert it to decimeters and 0.0254 to convert it to meters. Our example number of 5.375 is therefore equal to 136.5 millimeters, 13.65 centimeters, 1.365 decimeters and .1365 meters.

References

• The Engineering Toolbox: Inches and Decimal Equivalents
• Convert-me.com: Online Distance and Length Converter

Resources

• Science Made Simple: Metric Conversions & US Customary Unit Conversion
• SEO Consultants Directory: Conversion Tool - Convert Fractional and Decimal Inches