Area Calculator
Measuring a room, garden, or plot? Enter length and width and you will get area and perimeter right away. It helps you buy the right amount of materials.
TL;DR
- Start with a tape measure.
- Area and Perimeter Formulations: Area = Length × Width | Perimeter = 2 × (Length + Width)
- Example 1: Measuring a rectangular bedroom floor — Length: 5.0 meters, Width: 4.0 meters
How it works
Start with a tape measure. Record length and width in the same unit and keep it until the end. Real rooms are rarely perfect rectangles. Alcoves, door thresholds and built-in wardrobes break the shape, so treat each block as its own rectangle, multiply its sides, then add or subtract. For flooring, add 10 percent waste for straight lay and 15 percent for diagonal, because every row ends in a cut. For paint, divide wall area by coverage per liter and round up.
The math
Area counts surface. Multiply length by width and the unit squares itself. Perimeter counts edge. Add both lengths and both widths. Converting between metric and imperial only after the math keeps results clean.
Area multiplies the two sides and the unit becomes square. Perimeter adds the sides and stays linear. One square meter equals 10.764 square feet. One linear meter equals 3.281 feet. Keep them separate so you do not order skirting when you meant flooring.
Examples
Example 1: Measuring a rectangular bedroom floor
- Length: 5.0 meters, Width: 4.0 meters
- Calculate Area: 5.0 × 4.0 = 20.0 square meters (m²)
- Calculate Perimeter: 2 × (5.0 + 4.0) = 18.0 linear meters
- At 10 percent waste you order 22.0 square meters of flooring
Example 2: Sizing an outdoor fence line
- Length: 12 feet, Width: 8 feet
- Area: 12 × 8 = 96 sq ft
- Perimeter (Fencing required): 2 × (12 + 8) = 40 linear feet
Example 3: L-shaped kitchen with door cutout
- Main block: 6.0 × 4.0 = 24.0 square meters
- Alcove: 2.0 × 2.0 = 4.0 square meters, total 28.0
- Subtract door 0.9 × 2.0 = 1.8, net 26.2 square meters to buy
- Convert to US: 26.2 × 10.764 = 282.0 square feet
When to use it
✦ Flooring and Tile Installation
Calculate how many square meters of tiles or laminate flooring are required to cover a room, adding 10% for cuts.
✦ Wall Painting Budgets
Estimate wall surface areas to purchase the correct volume of paint without overspending.
✦ Land Sizing and Fencing
Determine the linear length of fencing material required to fully enclose a perimeter backyard plot.
⚠ Common mistakes
- Mixing Units: Multiplying measurements in inches by measurements in feet, producing nonsensical values. Standardize all inputs first.
- Ignoring Obstructions: Forgetting to subtract non-tileable surfaces such as fireplaces or kitchen island areas from total room calculations.
FAQ (2)
How do I convert square meters to square feet?
Multiply the area in square meters by 10.764 to convert it to square feet.
What does perimeter tell me?
Perimeter represents the distance around a shape, useful for baseboards, wallpaper borders, and fences.