Square Footage Calculator
Estimate Area & Material Costs for Any Shape
Total Area
Rectangle
Total sq ft
Estimating Square Footage & Project Costs
Whether you are painting a room, installing new flooring, or designing a home extension, calculating the precise square footage of a surface is the critical first step. An accurate measurement allows you to estimate material costs efficiently and prevent the frustration of running out of supplies mid-project.
Complex Surfaces
Rarely is a house perfectly rectangular. If your surface is complex in shape, the easiest method is to break the surface down into simple geometric shapes (rectangles, triangles), calculate their individual square footages, and add them together.
Reference Conversions
- 1 acre = 43,560 square feet
- 1 square yard = 9 square feet
- 1 square meter = 10.7639 square feet
- 1 square inch = 0.00694 square feet
Calculating Material Costs
Square footage dictates the cost of materials and labor for nearly all home improvement projects. Here is how measurements apply to specific renovations:
1. Painting a House
Professional painters base price quotations on the square footage of a property's walls. When calculating paint needed, you must subtract the area of doors and windows from the total wall area.
Total cost encompasses more than just the paint—it includes brushes, tape, drop cloths, and primer. Primer generally covers less area than paint, ranging between 200–400 square feet per gallon depending on the brand and wall texture.
2. Flooring Installation
Flooring costs vary wildly based on the material chosen for the area:
- Wood Flooring: Highly durable and visually versatile, but requires maintenance like sanding. Engineered hardwood provides better moisture resistance and is typically cheaper to install than solid hardwood.
- Laminate Flooring: Made with fiberboard and a plastic top layer. It is highly resistant to scratches and dents, and can even be installed over existing flooring, saving demolition costs. However, it cannot be refinished.
- Tile Flooring: Includes ceramic, glass, and natural stone. The price range is massive—from 60 cents per square foot to premium luxury stones costing hundreds. It is easy to clean but requires cold-weather radiant heating to remain comfortable.
3. Building a Home
Estimating the cost to build a house purely by square footage is challenging. Variables like foundation type, roof pitch, custom cabinetry, and local permit fees distort the baseline cost. Rather than using generic averages, it is best to get a precise estimate from a builder based on your architectural plans, then divide that estimate by the house's square footage to establish your true "cost per square foot" baseline.
Key Takeaways
- Always Add Overage: When purchasing materials like tile or hardwood, always buy 10% to 15% more square footage than your calculated area to account for cuts, breakages, and pattern matching.
- Subtract Obstacles: For wall painting or flooring, calculate the total area first, then calculate the area of obstacles (windows, doors, kitchen islands) and subtract them for an accurate "paintable" or "walkable" area.
- Complex Shapes: Don't guess the area of a strange room. Break the floor plan down into manageable rectangles and triangles, calculate each, and sum them.