Area calculator
Calculate the area and perimeter of a rectangle, circle or triangle.
Area
15 m²
Perimeter16 m
Calculations are based on Estonia's tax rates in force for 2026. Results are informational.
Last updated: 2026-06-03
Area formulas
The area of a rectangle is width × height, a circle is π × r², and a triangle is 0.5 × base × height. The perimeter is shown for the rectangle and the circumference for the circle.
How it is calculated
Formula
rectangle: A = a × b, perimeter 2(a + b); circle: A = πr², circumference 2πr; triangle: A = ½ × base × height.
Example
Rectangle 4 × 3 → area 12, perimeter 14.
Frequently asked questions
How do I find the area of a rectangle?+
The area of a rectangle is the product of its sides: A = a × b. The perimeter is 2(a + b).
How do I find the area of a circle?+
The area of a circle is A = πr², where r is the radius. The circumference is 2πr.