How to Convert Millimeter to Micrometer 1 mm = 1000 µm 1 µm = 0.001 mm Example: convert 15 mm to µm: 15 mm = 15 × 1000 µm = 15000 µm Popular Length Unit Conversions cm to inches inches to cm mm to inches inches to mm meters to feet feet to meters km to miles miles to km cm to feet feet to cm inches to feet feet to inches meters to yards