Square Footage Calculator
Calculate the square footage of rooms, houses, or land. Supports rectangle, circle, and triangle shapes. Get conversions and material estimates.
For rectangle
For rectangle
For circle
For triangle
For triangle
How do you calculate square footage of a room or house?
Rectangle/Square: Length × Width. Example: 12 ft × 10 ft = 120 sq ft. Multiple rooms: Calculate each separately, then add. L-shaped room: Divide into rectangles, calculate each, add together. Irregular shapes: Break into rectangles/triangles, calculate each section. Whole house: Add all rooms including closets, hallways. Include: Livable space, finished basements (if heated/cooled). Exclude: Garages (unless converted), unfinished basements, outdoor spaces. Tools needed: Measuring tape, calculator, paper. Tips: Measure to nearest inch, round up, double-check measurements, sketch layout with dimensions.
What is included and excluded in square footage?
INCLUDE: All finished, heated, livable space. Living rooms, bedrooms, bathrooms, kitchen, hallways, closets, finished attics (if 7ft+ ceiling), finished basements (above grade with windows). EXCLUDE: Unfinished spaces, garages (unless converted living space), unfinished basements, attics with <7ft ceiling, outdoor areas (patios, decks, porches), crawl spaces, storage sheds. Gray areas: Bonus rooms (include if finished/heated), sunrooms (include if heated/permanent), enclosed porches (depends on finish/heating). Appraisals: Official measurements follow ANSI standards. Different than tax assessor square footage (may include garage). Always clarify which measurement when buying/selling.
How much does square footage affect home value?
Price per square foot: Key metric. Example: $300,000 house ÷ 1,500 sq ft = $200/sq ft. Compare to neighborhood average. Larger homes: Generally worth more absolute value, but lower price per sq ft. Smaller homes: Higher price per sq ft. Impact varies by: Location (urban premium, suburban value), Quality (luxury finishes vs builder grade), Layout (efficient vs wasted space), Market (seller vs buyer market). Adding square footage: Finished basement adds 50-70% value vs main floor, bedroom addition adds more than extra living room, bathroom addition high ROI. Use to compare: Similar homes in area, determine fair price, plan additions/renovations.
How do I calculate square footage for flooring, paint, or materials?
Flooring: Calculate room sq ft, add 10% waste for cuts. Example: 200 sq ft room, buy 220 sq ft flooring. Tile: Add 15% for cuts/breakage. Carpet: Sold by sq yard (divide sq ft by 9). Paint: Wall sq ft ÷ 350 (coverage per gallon). Walls: (Length + Width) × 2 × Height - doors/windows. Example: 12×10 room, 8ft ceiling = 44 linear feet × 8ft = 352 sq ft walls. Ceiling: Same as floor sq ft. Roofing: Measured in squares (100 sq ft = 1 square). Pitch affects - multiply by factor (4:12 pitch = 1.06×). Always buy extra 10-15% for waste, future repairs, color matching.
What are common square footage mistakes to avoid?
Measuring mistakes: Not accounting for angles/corners, measuring wrong walls, decimal errors. Include feet and inches correctly. Calculation errors: Multiplying when should add, forgetting to convert inches to decimal feet (6" = 0.5 ft). Double counting: Counting same space twice in multiple rooms. Forgetting spaces: Closets, hallways, nooks, alcoves all count. Including non-livable: Garage, unfinished basement inflates number incorrectly. Not adding waste: Flooring/materials need 10-15% extra. Irregular shapes: Breaking into wrong shapes, miscalculating triangles (use ½ base × height). Prevention: Sketch layout first, measure twice, use sq ft calculator, have someone verify, keep notes organized.