Construction Calculator ft-in

On a job site you add 5 ft 7-3/8 in to 2 ft 9-5/8 in in your head, and one small slip becomes a wrong cut. This construction calculator works in feet, inches, and fractions directly, so the arithmetic stays exact.

It runs on a rational number engine — every value is kept as an exact fraction, so there is no floating-point rounding drift no matter how many steps you chain. Fraction precision goes from 1/2 down to 1/64, and each result shows as a fraction, a decimal, and in meters at the same time.

Built-in calculators cover the jobs you actually measure for:
• Stairs — rise, run, and stringer layout
• Rafters and roof slope
• Concrete volume, including 60 lb and 80 lb bag counts
• Boards, board feet, and stud spacing

A history keeps your last 50 calculations. It works without a connection, with no login and nothing to unlock later.

For carpenters, framers, remodelers, and anyone who does dimensional math in feet and inches all day.