Metric Converter

The metric converter translates common measurements between the International System of Units and familiar imperial or United States customary units. It covers length, mass, liquid volume, and temperature in one place, making it useful when a drawing, recipe, product specification, travel guide, or classroom problem uses a system that is unfamiliar to you. Select a category first because units from different physical dimensions cannot be converted meaningfully. A meter can become feet, but it cannot become pounds. Length conversions use the internationally defined relationships between meters and imperial units. One inch is exactly 25.4 millimeters, one foot is exactly 0.3048 meter, and one international mile is exactly 1,609.344 meters. The calculator converts the source value to meters and then from meters to the requested unit. This base-unit method keeps every pair consistent, whether you are changing centimeters to inches, kilometers to miles, or feet back to millimeters. Mass calculations follow the same pattern with kilograms as the base. The international avoirdupois pound is exactly 0.45359237 kilogram, while an ounce is one sixteenth of a pound. These are mass conversions, not force conversions, which matters in technical work. Volume uses liters as its base and applies United States liquid measures: one US gallon equals exactly 3.785411784 liters and one US fluid ounce equals 29.5735295625 milliliters. Imperial gallons used in the United Kingdom are larger, so always confirm which gallon a source document means. Temperature differs because its scales have different zero points as well as different interval sizes. Celsius to Fahrenheit uses Fahrenheit = Celsius times 9 divided by 5, plus 32. Kelvin shares the Celsius interval but begins at absolute zero, so Kelvin = Celsius plus 273.15. The converter performs those offset calculations separately instead of treating temperature like a simple ratio. Results are rounded only for display, retaining up to ten decimal places so small engineering measurements remain useful without overwhelming everyday conversions. Very large or repeating decimal results may still require rounding for a particular project. For construction, machining, medicine, regulated trade, or laboratory work, follow the tolerance and significant-figure rules supplied with the job. This tool provides a fast arithmetic reference, while the source specification remains the authority for precision and unit definitions.