Square Footage Calculator
Calculate square footage from length and width, plus total cost.
Try an example
180 sq ft
About this calculator
How This Square Footage Calculator Works
Enter a length and width, and the calculator returns the square footage — plus the total cost if you enter a price per square foot.
Worked Example
A 12 ft × 15 ft room is 180 square feet — at $5/sq ft, that comes to $900 in total material cost.
The Formula
Square footage = Length × Width. For an irregularly shaped room or area, split it into rectangular sections, calculate each one separately, then add the results together — this calculator handles one rectangle at a time.
A Note on Ordering Materials
Most flooring, tile, and paint projects need some allowance beyond the exact square footage — for cuts, waste, pattern matching, and mistakes. Ordering 5-10% more than the calculated area is standard practice, and even more for materials with a repeating pattern that needs to be matched at seams.
Worked example
A 12 ft × 15 ft room is 180 square feet — at $5/sq ft, that's $900 in total material cost.
Frequently asked questions
How do I measure an irregularly shaped room?
Split it into rectangles, calculate each section's square footage separately, then add them together — this calculator handles one rectangle at a time.
Should I round up when ordering flooring or paint?
Yes — most materials are sold with some allowance needed for cuts, waste, and pattern matching, so ordering 5-10% more than the exact square footage is standard practice.