# Area Calculator

Calculate area for rectangles, circles, and triangles. Results in square feet, square meters, square yards, and acres. Free area calculator.

## What this calculates

Whether you are measuring a room, planning a garden, or estimating material needs, this area calculator handles the three most common shapes: rectangles, circles, and triangles. Enter your dimensions and get the area in multiple units including square feet, square meters, square yards, and acres.

## Inputs

- **Shape** — options: Rectangle, Circle, Triangle
- **Length** (ft) — min 0 — Length for rectangle, base for triangle
- **Width / Height** (ft) — min 0 — Width for rectangle, height for triangle
- **Radius** (ft) — min 0 — Only used for circle shape

## Outputs

- **Area** (ft²)
- **Area** (m²) — 1 ft² = 0.0929 m²
- **Area** (yd²) — 1 yd² = 9 ft²
- **Area** (acres) — 1 acre = 43,560 ft²
- **Formula** — formatted as text

## Details

Area formulas used:

  - Rectangle: A = length × width

  - Circle: A = πr² (pi times radius squared)

  - Triangle: A = ½ × base × height

Unit conversions provided:

  - 1 square foot (ft²) = 0.0929 square meters (m²)

  - 1 square yard (yd²) = 9 square feet (ft²)

  - 1 acre = 43,560 square feet (ft²)

For construction projects, the rectangle formula covers most room and wall calculations. The circle formula is essential for round patios, pools, and columns. The triangle formula helps with gabled walls and oddly shaped lots.

## Frequently Asked Questions

**Q: How do I calculate the area of an irregular shape?**

A: Break the irregular shape into rectangles, triangles, and circles. Calculate each piece separately and add them together. For very irregular shapes, the best approach is to approximate using a grid overlay.

**Q: What is the difference between area and perimeter?**

A: Area measures the surface enclosed by a shape (in square units). Perimeter measures the total length of the boundary around a shape (in linear units). Area tells you how much space is inside; perimeter tells you how much fencing you need around it.

**Q: How do I convert square feet to square meters?**

A: Multiply square feet by 0.0929. For example, 100 ft² = 100 × 0.0929 = 9.29 m².

**Q: How many square feet are in an acre?**

A: One acre equals 43,560 square feet. An acre is roughly the size of a football field (which is 48,000 ft² including end zones).

**Q: Which measurements do I use for a triangle?**

A: Use the base (any one side) and the height (the perpendicular distance from that base to the opposite vertex). The height must be measured at a right angle to the base, not along a side.

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Source: https://vastcalc.com/calculators/math/area
Category: Math
Last updated: 2026-04-21