Calculate area and perimeter for 9 shapes — rectangle, square, circle, triangle, trapezoid, parallelogram, ellipse, sector, and rhombus
This free area calculator handles nine common geometric shapes — rectangle, square, circle, triangle, trapezoid, parallelogram, ellipse, circular sector, and rhombus. Pick a shape, type the dimensions, and you get both the area and the perimeter (where applicable) in real time, along with the formula and calculation breakdown so you can follow every step.
A = w × h
Perimeter = 2(w + h)
A = s²
Perimeter = 4s
A = π r²
Circumference = 2πr
A = ½ b h
Requires base and height
A = ½(a+b) h
Sum of parallel sides × height ÷ 2
A = b × h
Perimeter = 2(b + s)
A = π a b
Perimeter ≈ Ramanujan approximation
A = (θ/360) π r²
Arc + 2 radii for perimeter
A = ½ p q
p and q are the diagonals
From basic rectangles and circles to trapezoids, ellipses, and circular sectors — all in one tool.
Get both measurements at once, saving you from switching between separate calculators.
Every result includes the formula used and a step-by-step breakdown so you can verify the math.
Control decimal places from 0 to 8 — rough estimates for construction or high precision for engineering.
Flooring, tiling, and paint coverage all start with an area and perimeter calculation.
Work out lawn size for seed, mulch, or sod. Calculate circular flower beds with the sector tool.
Check geometry homework — nine shapes with step-by-step breakdowns help you learn the formulas.
Quick cross-section calculations for beams, pipes, and building footprints.
Calculator
Basic calculator for mathematical operations
Average Calculator
Calculate the average of a set of numbers
GST Calculator
Calculate GST, add or remove tax from prices
Unit Converter
Convert between different units of measurement
Percentage Calculator
Calculate percentages and percentage changes
Trigonometric Functions
Calculate sine, cosine, tangent and other trig functions