21 ft to in conversion result above is displayed in three different forms: as a decimal (which could be rounded), in scientific notation (scientific form, standard index form or standard form in the United Kingdom) and as a fraction (exact result). Every display form has its own advantages and in different situations particular form is more convenient than another. For example usage of scientific notation when working with big numbers is recommended due to easier reading and comprehension. Usage of fractions is recommended when more precision is needed.
If we want to calculate how many Inches are 21 Feet we have to multiply 21 by 12 and divide the product by 1. So for 21 we have: (21 × 12) ÷ 1 = 252 ÷ 1 = 252 Inches
So finally 21 ft = 252 in
