Area Calculator

Calculate the area of the most common 2D shapes in one place. Choose the shape, enter the dimensions, pick the unit, and get the area with formula steps.

Area formulas used

Below are the formulas the calculator uses depending on the chosen shape.

1. Rectangle / Square

Formula: \( A = w \times h \)

Where: \( w \) = width, \( h \) = height

2. Triangle

Formula: \( A = \frac{b \times h}{2} \)

Where: \( b \) = base, \( h \) = height

3. Circle

Formula: \( A = \pi r^2 \)

Where: \( r \) = radius

4. Trapezoid

Formula: \( A = \frac{(a + b) \times h}{2} \)

Where: \( a \) and \( b \) are the parallel sides, \( h \) is the height.

5. Parallelogram

Formula: \( A = b \times h \)

Where: \( b \) = base, \( h \) = perpendicular height

6. Ellipse

Formula: \( A = \pi a b \)

Where: \( a \) = semi-major axis, \( b \) = semi-minor axis

7. Circular sector

Formula: \( A = \pi r^2 \times \frac{\theta}{360^\circ} \)

Where: \( r \) = radius, \( \theta \) = central angle in degrees

How to calculate area (step-by-step)

Step 1: Identify the shape you are working with.

Step 2: Measure the required dimensions (sides, base, height, radius...). Always keep them in the same unit.

Step 3: Plug the numbers into the correct formula above.

Step 4: Express the result in squared units, e.g. m², cm², in², ft².

This tool automates all those steps for you and also presents the structure of the formula for transparency.

Area Calculator – FAQ