Feet to Inches (ft to in) conversion calculator for Length conversions with additional tables and formulas. How many inches are in a foot? Use this easy and mobile-friendly calculator to convert between feet and inches . Just type the number of feet into the box and hit the Calculate button. Convert 1 ft to common lengths ... What is 1 feet in in? To convert 1 ft to in multiply the length in feet by 12.0. The 1 ft in in formula is [in] = 1 " 12.0. Thus, for 1 feet in inch we get 12.0 in. Use this tool to convert between different units of height, such as centimeters, meters, feet and inches . Learn how to calculate your height in cm from inches or feet , and see a conversion chart.