Free Square Footage Calculator

Calculate area instantly for flooring, carpet, tiles, landscaping & construction projects

*optional materials waste factor
*optional materials cost
Answer:
Square Feet 0
Square Inches 0
Square Yards 0
Square Meters 0
Acres 0

How to Calculate Square Footage

Square footage is area expressed in square feet. This calculator helps you find the square footage, square inches, square yards, square meters, or acres for buildings, homes, gardens, flooring, carpet, tiles, or construction projects.

Calculate Square Footage in 3 Easy Steps:

1. Select Your Shape: Choose from 8 different area shapes including square, rectangle, circle, triangle, trapezoid, and more complex shapes like rectangle borders and annulus.

2. Enter Measurements: Input your measurements in your preferred units - feet, inches, yards, centimeters, or meters. You can mix different units for different measurements, and the calculator will handle the conversions automatically.

3. Add Optional Details: Enter the quantity if you have multiple areas, add a waste factor percentage for material ordering, and input material costs to get total project estimates.

Supported Measurement Units

This calculator accepts measurements in both US and metric units:

Tip: If you have a measurement like 7'3", you can enter it as 7.25 feet (since 3"/12" = 0.25 ft).

Square Footage Formulas for Different Shapes

Illustration of a square with one side labeled for area calculation. Side

Square

Formula: Area = Side × Side

A square has all four sides equal. Simply enter the length of one side to calculate the area.

Illustration of a rectangle with length and width labeled for area calculation. Length W

Rectangle

Formula: Area = Length × Width

The most common calculation. Multiply the length by the width to get the area in square feet.

Illustration of a circle with its diameter labeled for area calculation. Diameter

Circle

Formula: Area = π × (Diameter ÷ 2)²

Enter the diameter (distance across the circle through the center) to calculate the circular area.

Illustration of a triangle with sides A, B, and C labeled for area calculation. A B C

Triangle

Formula: Area = √[s(s-a)(s-b)(s-c)] where s = (a+b+c)/2

This calculator uses Heron's formula. Enter all three side lengths to calculate the area.

Illustration of a trapezoid with parallel sides A, B, and height labeled for area calculation. A B h

Trapezoid

Formula: Area = ((Side A + Side B) ÷ 2) × Height

A trapezoid has two parallel sides. Enter both parallel sides and the perpendicular height between them.

Illustration of a rectangular border's area, calculated by subtracting the inner area from the outer area. Border

Rectangle Border / Annulus

Formula: Border Area = Total Area - Inner Area

Calculate the area of borders, frames, or rings by subtracting the inner area from the outer area.

Unit Conversion Reference

Use these conversion factors to convert between different area units:

From To Multiply By
Square Feet Square Inches 144
Square Feet Square Yards 0.11111
Square Feet Square Meters 0.092903
Square Feet Acres 0.00002296
Square Yards Square Feet 9
Square Meters Square Feet 10.7639

Common Uses for Square Footage Calculator

🏠 Flooring Projects

Calculate how much hardwood, laminate, tile, or vinyl flooring you need for rooms, hallways, and entire homes.

🎨 Painting & Wallpaper

Determine wall and ceiling coverage to estimate paint gallons or wallpaper rolls needed.

🪴 Landscaping

Calculate areas for sod, mulch, gravel, pavers, decking, and garden beds.

🏗️ Construction

Estimate materials for roofing, siding, drywall, and other construction projects.

🛋️ Carpet & Rugs

Find the right carpet size and estimate costs for residential or commercial spaces.

💰 Cost Estimation

Calculate total material costs by entering price per square unit with optional waste factor.

Tips for Accurate Measurements

Frequently Asked Questions

How accurate is this square footage calculator? +
Our calculator uses precise mathematical formulas to ensure accuracy. Results are calculated to two decimal places for square footage. However, for critical projects, we always recommend verifying measurements and consulting with professionals.
Can I calculate area for irregular shapes? +
For irregular or L-shaped rooms, break them into separate rectangles or squares, calculate each area individually, then add them together for your total square footage.
What units does the calculator support? +
Our calculator supports feet, inches, yards, centimeters, and meters. You can mix different units for different measurements, and the calculator will automatically convert them for accurate results.
How much waste factor should I add? +
For most projects, add 5-10% extra. For tile work with complex patterns, add 10-15%. For carpet or wood flooring, 5-7% is typical. Always round up when ordering materials.
Is this calculator free to use? +
Yes! Our square footage calculator is 100% free with no hidden fees, subscriptions, or sign-ups required. You can use it for personal or commercial projects.
Can I use this for commercial projects? +
Absolutely! Contractors, builders, and professionals are welcome to use our calculator for their commercial projects. It's free for both personal and commercial use.
Does it work on mobile devices? +
Yes! Our calculator is fully responsive and works perfectly on smartphones, tablets, and desktop computers. Calculate on the go at your job site or project location.
How do I calculate flooring for multiple rooms? +
Calculate each room separately, then add the results together. Use the "Quantity" field if you have multiple identical rooms. Don't forget to add your waste factor!
Do you store my calculations or data? +
No. All calculations happen in your browser. We don't collect, store, or track any of your measurements or personal data. Your privacy is protected.
What if I need help with my calculation? +
Feel free to contact us through our contact page. We're happy to help answer questions about using the calculator or understanding your results.