Калькулятор площади
The detailed guide below is currently available in English.
The four area formulas used here
Rectangles multiply length by width. Triangles take half of that: ½ × base × height, where the height is measured perpendicular to the base. A trapezoid averages its two parallel sides and multiplies by the perpendicular distance between them: ½(a + b)h. A circle uses π times the radius squared. Each tab applies one unit to all dimensions so the result lands in that unit squared.
Square-unit conversions worth memorizing
Square units grow fast: one meter is 100 centimeters, but one square meter is 10,000 square centimeters. On the imperial side, one square foot is 144 square inches and one square meter is about 10.764 square feet. The rows under the result do these conversions for you, which is useful when plans are drawn in one system and materials are sold in the other.
Частые вопросы
The height of my triangle is slanted — does that matter?
Use only the perpendicular height (the shortest distance from the base to the opposite corner). If you know two sides and the angle between them instead, compute height = side × sin(angle) first, or use the full triangle calculator with those values.
Can I mix meters for one side and centimeters for another?
Convert one of them first. Mixing units inside a formula silently inflates or shrinks the answer by a factor of 100 or more, which is the most common source of wrong area results.