Skip to content

Square Footage Calculator

Calculate area for any room shape in seconds. Rectangles, circles, triangles, L-shapes — in ft² or m².

—
—
0.00Total ft²
0.00Total m²

2 rooms · 1 ft² = 0.0929 m²

How the Square Footage Calculator Works

Select your room's shape, choose your preferred unit (feet or meters), then enter the dimensions. The calculator instantly shows the area in both square feet and square meters — no manual conversion needed. For complex rooms, use the L-Shape option by splitting the floor plan into two rectangles.

Common Uses

  • Flooring and tiling: Calculate how many boxes of hardwood, laminate, or tile you need. Add 10% for waste and cutting errors.
  • Paint coverage: One gallon covers roughly 350–400 ft² (32–37 m²) per coat. Knowing your wall area prevents over-buying.
  • Real estate comparisons: Convert between square feet (North America) and square meters (Europe, Asia) when comparing listings.
  • HVAC sizing: Air conditioner and heating unit capacity is often specified per square foot. Get the right BTU rating by knowing your room size.

Now Handles Every Room in One Session

The calculator now manages multiple rooms at once. Add as many rooms as you need — living room, two bedrooms, a hallway — give each one a name, enter length and width, and the grand total updates instantly. A global ft/m toggle switches every room at once, so you never convert manually.

The grand total shows in both ft² and m² side by side — useful when your flooring quote is in one unit and your permit application requires the other. Each room also gets a proportional visual panel so you can eyeball relative sizes at a glance. Results are saved in localStorage, so a refresh won't wipe your work. No export or sharing yet — just the numbers you need.

When to Use a Square Footage Calculator

Calculate square footage when estimating flooring materials (hardwood, tile, carpet), paint coverage (1 litre covers ~10 m² / one gallon covers ~350 sq ft), wallpaper, insulation, and landscaping sod. Also useful for comparing rental or real estate listings — Canadian listings typically use square feet; European listings use square metres (1 m² = 10.764 sq ft).

Pair this tool with our Cooking Converter, Unit Converter, Temperature Converter, or Fuel Consumption Calculator for all your home-project estimates.

How to Measure a Room's Square Footage

For rectangular rooms: length × width. For L-shaped rooms: divide into two rectangles, calculate each, then add. For triangular sections: (base × height) / 2. Always measure at the widest points, including closets and alcoves. Add 10% overage for flooring to account for cuts, waste, and future repairs. For paint, divide total wall area (perimeter × ceiling height, minus doors and windows) by the paint's coverage rate. Pro tip: measure in the same unit throughout and convert once at the end to avoid compounding errors.

Frequently Asked Questions

How do I convert square feet to square meters?
Multiply square feet by 0.0929 to get square meters. For example, 200 ft² × 0.0929 = 18.58 m². This calculator does the conversion automatically in both directions — just enter your dimensions in your preferred unit.
How do I measure an L-shaped room?
Mentally divide the L-shape into two separate rectangles. Measure the length and width of each rectangle individually, then add the two areas together. Our L-Shape mode does this automatically — just enter the four measurements.
How much extra material should I buy for flooring?
A standard rule of thumb is to add 10% to your calculated area to account for cutting waste, pattern matching, and future repairs. In rooms with many angles or diagonal installations, increase that buffer to 15%. Always round up to the nearest full box when purchasing.
How do I convert square feet to square metres?
1 square foot = 0.0929 square metres. To convert: sq ft × 0.0929 = m². To convert back: m² × 10.764 = sq ft. A 1,000 sq ft apartment = ~92.9 m². A 100 m² apartment = ~1,076 sq ft. Canadian MLS listings use square feet; European and many international listings use square metres.
How much paint do I need for a room?
Calculate wall area: add up (length × height) for each wall, then subtract door area (~1.9 m² / 20 sq ft each) and window area (~1.1 m² / 12 sq ft each). One litre of paint covers approximately 10–12 m² (110–130 sq ft) for one coat. Divide your net wall area by the coverage rate, then multiply by the number of coats (usually 2). Add 10% for touch-ups.

You might also need

See all tools →

Complementary tools based on what you're doing

By Bam's Thinkery — Updated