Square Footage Calculator
Add one or more rectangular areas (rooms, closets, hallways, etc.) to get your total square footage. Great for flooring, tile, carpet, and renovation estimates.
How to figure out square footage quickly
Square footage tells you how much flat surface area a space covers. If you are buying flooring, carpet, laminate, vinyl planks, tile, or even planning furniture layout, knowing your total area is one of the most useful first steps. The simplest formula is:
Length × Width = Area
If your measurements are in feet, your result is in square feet (sq ft). For example, a room that is 12 feet long and 10 feet wide is 120 square feet.
When this calculator is most useful
- Estimating flooring material before shopping
- Comparing room sizes while house hunting
- Planning renovation budgets
- Adding up several rooms for whole-home projects
- Including a waste factor so you do not under-order material
Step-by-step: use the calculator above
1) Pick your measurement unit
Choose feet, inches, yards, or meters. The calculator converts everything to square feet behind the scenes.
2) Enter each area
For every rectangular section, enter length and width. You can also set quantity for repeated spaces (for example, two closets with the same dimensions).
3) Add extra material percentage
Most flooring jobs need additional material for cuts, defects, and layout direction. A common starting point is 10%.
4) Click calculate
You will get total square footage, total with waste, plus conversions to square yards, square meters, and acres.
What if the room is not a perfect rectangle?
Most real spaces are irregular. The easiest method is to break the space into smaller rectangles, calculate each one, and add them together. That is exactly why this tool supports multiple areas.
- Split L-shaped rooms into two rectangles
- Measure hallways separately
- Treat closets as separate sections
- Subtract fixed openings only if your installer recommends it
Example calculation
Let’s say you are installing flooring in three sections:
- Living Room: 18 × 14 ft = 252 sq ft
- Hallway: 12 × 4 ft = 48 sq ft
- Closet: 6 × 3 ft = 18 sq ft
Total = 318 sq ft. With a 10% waste factor: 318 × 1.10 = 349.8 sq ft. You would usually round up to the next full box or bundle based on your product packaging.
Common mistakes that cause bad estimates
- Mixing units (feet in one room, inches in another) without converting
- Forgetting to include small areas like closets or entries
- Not adding waste for cuts and pattern matching
- Rounding down too aggressively
- Using wall measurements when you need floor measurements
Square footage conversion tips
Useful reference values
- 1 square yard = 9 square feet
- 1 square meter = 10.7639 square feet
- 1 acre = 43,560 square feet
If you are buying carpet, many suppliers quote in square yards. If you are reviewing architectural documents, dimensions may appear in meters. Conversions keep your budget consistent.
How much extra should you buy?
It depends on material and layout complexity:
- 5% for simple square rooms with straightforward installation
- 8%–10% for typical homes and moderate cuts
- 12%–15% for diagonal patterns, herringbone, or many corners
When in doubt, ask your installer for a project-specific recommendation.
Final takeaway
To figure out square footage accurately, measure carefully, split irregular layouts into smaller sections, add totals, and include an appropriate waste percentage. A few extra minutes of measurement can save money, reduce delays, and help your project run smoothly from start to finish.