Square Footage Calculator

The Square Footage Calculator is a versatile area calculator that handles rectangles, triangles, circles, trapezoids, ellipses, L-shaped rooms, and multi-room layouts. Whether you are measuring a bedroom for new flooring, calculating a lot size for landscaping, or estimating paint for a renovation project, this tool provides instant results with unit conversions, material estimates, cost calculations, and step-by-step formulas.

Square Footage Formulas

How to Calculate Square Footage

1. Select your shape: Choose rectangle, triangle, circle, trapezoid, ellipse, L-shape, or multi-room mode depending on your area's shape.
2. Enter measurements: Input the dimensions in your preferred unit (feet, inches, meters, centimeters, or yards). Use a tape measure for accurate results.
3. Add cost estimate (optional): Enter a price per square foot to calculate total cost for your project — useful for flooring, painting, or real estate.
4. Review results: Get the area in multiple units, a visual diagram, step-by-step math, material estimates for paint/flooring/tile, and comparisons to familiar spaces.

Common Room Sizes Reference

Tips for Measuring Square Footage

• Break complex rooms into rectangles: An L-shaped room is two rectangles. Measure each section separately and add the areas.
• Always add waste factor: For flooring, add 10% for straight layouts and 15% for diagonal or patterned layouts to account for cuts.
• Round up for materials: When ordering paint, tile, or flooring, always round up to the next whole unit to avoid running short.
• Measure at floor level: For flooring projects, measure at floor level rather than at waist height, as walls may not be perfectly vertical.
• Exclude closets and alcoves: Decide whether to include or exclude closet areas based on your project needs — real estate listings typically include them.

Unit Conversion Quick Reference

• 1 square foot = 144 square inches = 0.0929 square meters
• 1 square meter = 10.7639 square feet
• 1 square yard = 9 square feet
• 1 acre = 43,560 square feet = 4,047 square meters

Frequently Asked Questions

How do I calculate square footage?

For a rectangle or square, multiply length times width. For example, a 12 ft by 14 ft room is 168 square feet. For other shapes, use the appropriate formula: triangles use half base times height, circles use pi times radius squared.

How do I calculate square footage of an irregularly shaped room?

Break the irregular shape into simpler shapes like rectangles, triangles, or circles. Calculate the area of each section separately, then add them together. For L-shaped rooms, divide into two rectangles. For rooms with alcoves, calculate the main area plus the alcove area.

How many square feet are in an acre?

One acre equals 43,560 square feet. An acre is roughly the size of a football field without the end zones (which is 48,000 sq ft). To convert square feet to acres, divide by 43,560.

How much flooring do I need for a room?

Calculate the room's square footage by multiplying length times width, then add 10% for waste from cuts and fitting. For diagonal or patterned installations, add 15% instead. For example, a 12×14 ft room is 168 sq ft, so you would need approximately 185 sq ft of flooring material.

How do I convert square feet to square meters?

Divide square feet by 10.7639 to get square meters. For example, 500 square feet equals approximately 46.45 square meters. Conversely, multiply square meters by 10.7639 to get square feet.

Additional Resources

• Square foot - Wikipedia
• Area - Wikipedia