Area Calculator

Calculate area in square metres for rectangles, triangles, circles, walls, and rooms. Subtract windows and doors to get the net area for painting, tiling, or insulation.

Construction

Width m

Height m

Length m

Width m

Height

Length m

Width m

Base m

Height m

Radius m

Subtract windows and doors

Windows

Width m

Height m

Qty

Doors

Width m

Height m

Qty

Enter the dimensions and you will see the area.

Results are informational. Calculation is based on your input and public rules, official accounting may differ. For accuracy, confirm the final result if needed from the appropriate official source or specialist. See the terms of use.

How it works?

Enter the dimensions in metres and the area appears instantly in square metres (m²).

Rectangle: length × width. Triangle: base × height ÷ 2. Circle: π × radius².

Wall: width × height, with optional subtraction for windows and doors. Room: floor area from length × width, plus total wall area (perimeter × height) if you add height - also with optional openings.

The result updates live as you type. Use the share button to save or send the calculation with all values in the URL.

Frequently asked questions

How do I calculate area in square metres?

Multiply length by width in metres. For example, a 5 × 3 metre room has an area of 15 m². This calculator does it instantly - enter dimensions and the result appears.

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How do I calculate wall area for painting?

Use the Wall tab: enter the wall width and height. Then subtract any windows and doors by entering their dimensions and quantity. The net area is what you need to paint.

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How do I find the total wall area of a room?

Use the Room tab: enter length, width, and height. The calculator computes 2 × (length + width) × height for the total wall area, and you can subtract window and door openings.

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What is the formula for the area of a circle?

The area of a circle is π × radius². Enter the radius in metres and the calculator gives you the area in square metres instantly.

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How many square metres of tiles do I need?

Measure the floor length and width in metres, then use the Rectangle or Room tab. For walls, add height and subtract openings. The net area tells you how many square metres of tiles to buy - add 5-10% for cuts and waste.

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