How to Convert cm, Inches & Feet to Square Feet

You have finally picked the perfect flooring. The samples look amazing, the price is right, and you are ready to order — but then comes the question that trips up almost everyone: how much do you actually need?

Whether you are measuring a room in feet, looking at tile dimensions in centimetres, or working with furniture specs listed in inches, you will almost always need to convert those measurements into square feet before you can buy materials, get a quote, or plan a layout accurately.

This guide explains exactly how to make every conversion — with simple formulas, real examples, and a free tool you can use right now.

What Is a Square Foot?

A square foot (sq ft or ft²) is a unit of area in the imperial measurement system. It represents the surface of a square where each side measures exactly one foot — that is 12 inches, or 30.48 centimetres per side.

Square footage became the go-to standard for interior spaces because it gives you a single number that describes the full surface area of a room, floor, or wall. Unlike measuring just the length or the width, square footage captures both dimensions at once — which is exactly what you need when ordering materials that cover a surface.

Interior designers, flooring installers, contractors, and homeowners all use square feet for the same reason: it is the most practical unit for calculating how much of a material you need.

How to Convert Centimetres (cm) to Square Feet

Centimetre measurements appear on tiles, fabric swatches, wallpaper rolls, and most imported flooring products. The formula is:

Step-by-step example

You are looking at a 60 cm × 60 cm porcelain floor tile. Here is how to find how much floor area each tile covers:

How to Convert Inches to Square Feet

Inches are the standard for US flooring specs, furniture dimensions, and fabric widths. The formula is:

Step-by-step example

You want to know how many 24-inch × 24-inch tiles you need for a 100 sq ft bathroom:

How to Convert Feet to Square Feet

If your room dimensions are already in feet, the conversion is the simplest of all:

Step-by-step example

Your living room measures 12 ft wide by 15 ft long:

Why Square Footage Matters in Interior Design

Square footage is the foundation of almost every interior design decision. Here is where it makes the biggest difference:

• Flooring & carpet — order the right quantity, avoid costly shortfalls or wasted excess
• Tile planning — calculate full tiles, edge cuts, and waste allowance accurately
• Rug sizing — choose a rug that anchors your furniture at the correct visual scale
• Paint & wallpaper — most products state coverage per sq ft, so you need the area first
• Furniture layout — ensure sofas, dining tables, and beds are proportionate to the room
• Renovation budgeting — contractors price flooring, tiling, and plastering per square foot

Common Room Sizes in Square Feet

Not sure if your room is big or small? Use these standard dimensions as a quick benchmark:

Room	Typical Size	Square Feet
Small bedroom	10 ft × 10 ft	100 sq ft
Standard bedroom	10 ft × 12 ft	120 sq ft
Master bedroom	14 ft × 16 ft	224 sq ft
Living room (avg)	15 ft × 20 ft	300 sq ft
Kitchen (standard)	10 ft × 15 ft	150 sq ft
Full bathroom	5 ft × 8 ft	40 sq ft
Area rug (8×10)	8 ft × 10 ft	80 sq ft
Large format tile (60cm)	60 cm × 60 cm	3.88 sq ft

Quick Conversion Reference

Bookmark this section for fast lookups the next time you are shopping for tiles, flooring, or rugs.

Frequently Asked Questions

Here are the most common questions people ask when converting measurements for interior design projects.