Convert 40 centimeters to inches using a simple formula or a conversion table. Find out how many inches are in 40 cm and see alternative spellings and languages. Convert 40cm into inches. How tall is 40 cm in inches? How many inches is 40 cm? The answer is: 15.75. Convert Centimeters to Inches Use this online tool to convert centimeters to inches easily and quickly. Enter the value in cm and get the result in in, or vice versa, with a conversion table and formula. How many inches is 40 cm? Convert 40 centimeters to inches. Here you can easily find the answer and the conversion procedure to convert 40 cm to inches.