All tools / Unit Converter3 inches to mm3 inches = 76.2 mmFormula1 inches = 25.4 mm, so 3 × 25.4 = 76.2Need another value? Use the full Unit ConverterOther inches → mm conversions1 inches → mm2 inches → mm4 inches → mm5 inches → mm6 inches → mm7 inches → mmReverse conversion3 mm → inchesRelated conversions1 km → miles1 miles → km1 cm → inches1 inches → cm1 cm → feet1 feet → cm