Rectangle Calculator
Rectangle calculator: enter length and width to get the area, perimeter and diagonal at once. Useful for rooms, gardens, screens and materials.
Formula
Area = l × w ; Perimeter = 2(l + w)
Use it from the API
curl "https://moltcalc.com/api/calc/rectangle?length=10&width=6"
See the API docs for every endpoint and the input schema.
FAQ
How do I find the area of a rectangle?+
Multiply length by width. A 10 by 6 rectangle has an area of 60 square units, whatever unit you measured the sides in.
How do I calculate the diagonal of a rectangle?+
Use the Pythagorean theorem: the diagonal is the square root of length squared plus width squared. For 10 by 6 that is about 11.66 units.
What is the perimeter of a rectangle?+
Add up all four sides, which works out to 2 × (length + width). A 10 by 6 rectangle has a perimeter of 32 units.
Related calculators
Circle Calculator
Circle calculator: enter the radius to get the area, circumference and diameter in one step, with the pi formulas and working written out for you.
Triangle Area Calculator
Triangle area calculator using base and height. Get the area from the half base times height formula, with each step of the working shown.