计算8种常见几何图形的面积 — 矩形、正方形、圆形、三角形、梯形、平行四边形、菱形和椭圆。即时显示结果并展示公式。纯客户端处理。
矩形：长度 × 宽度
圆形：π × 半径²
三角形：½ × 底边 × 高度
此面积计算器计算8种常见几何图形的面积和周长。只需选择图形，输入所需尺寸，选择单位系统，即可获得即时结果和使用的公式。所有计算均在您的浏览器中完成 — 不会向任何服务器发送数据。非常适合学生、工程师、设计师和任何需要快速几何计算的人。
This calculator supports 8 common geometric shapes: Rectangle, Square, Circle, Triangle, Trapezoid, Parallelogram, Rhombus, and Ellipse. Each shape requires specific measurements to calculate both area and perimeter.
Yes, the area calculator is completely free to use. No registration, no ads, and no limits. All calculations happen in your browser — no data is sent to any server.
Yes, you can choose between centimeters (cm), meters (m), inches (in), and feet (ft). The calculator automatically converts the results to the corresponding area units (cm², m², in², ft²).
Yes, after calculating, the formula used is displayed in a formula box below the results. This helps you understand the math behind the calculation and is useful for learning and verification.
Area measures the space inside a shape (in square units), while perimeter measures the total length of the shape's boundary (in linear units). This calculator provides both values for all supported shapes.
This calculator focuses on standard geometric shapes. For irregular shapes, you can break them down into simpler shapes (like rectangles and triangles), calculate each area separately, and then sum them up.
Yes, the calculator uses standard mathematical formulas and provides results with up to 4 decimal places for precision. For engineering or critical applications, always verify with additional methods.
Absolutely. The calculator is fully responsive and works seamlessly on smartphones, tablets, and desktop computers.