Square Footage Calculator
Room area for flooring, paint and materials.
Enter your values
Enter the length in ft.
Enter the width in ft.
Enter the waste allowance in %.
Enter the material price in $/sq ft.
Results update instantly as you type — no submit needed. Your values are remembered on this device, and the shareable link reopens the calculator with exactly these numbers.
- Area
- 216 sq ft
- With waste allowance
- 237.6 sq ft
- In square metres
- 20.07
- Material cost
- $831.6
- Perimeter
- 60 ft
Quick answer
Square footage is length × width; add 10% waste for flooring cuts and pattern matching.
Area = length × width
At a glance
| What it does | Room area for flooring, paint and materials. |
|---|---|
| Category | Home & DIY |
| Inputs needed | Length, Width, Waste allowance, Material price |
| Main output | Area |
| Formula | Area = length × width |
| Cost | Free — no sign-up, no download |
How to use the Square Footage Calculator
- 1Measure the room's length and width in feet.
- 2Set a waste allowance for cuts.
- 3Add material price for a cost estimate.
Inputs explained
- Length(ft)
- Enter the length in ft.
- Width(ft)
- Enter the width in ft.
- Waste allowance(%)
- Enter the waste allowance in %.
- Material price($/sq ft)
- Enter the material price in $/sq ft.
Worked example
Using the values the calculator loads with:
Inputs
- Length18 ft
- Width12 ft
- Waste allowance10 %
- Material price3.50 $/sq ft
Results
- Area216 sq ft
- With waste allowance237.6 sq ft
- In square metres20.07
- Material cost$831.6
- Perimeter60 ft
Frequently asked questions
How much waste should I allow?
10% for straight-lay flooring, 15% for diagonal patterns and 20% for herringbone or heavily patterned material.
How do I handle L-shaped rooms?
Split them into rectangles, calculate each separately and add the areas together.
What do I need to enter into the Square Footage Calculator?
Just 4 values: length, width, waste allowance, material price. Every field starts with a realistic example, so you can change one number at a time and watch the result update instantly.
How does the Square Footage Calculator work out the answer?
Square footage is length × width; add 10% waste for flooring cuts and pattern matching. It applies the formula Area = length × width and shows the working so you can check each step by hand.
Is the Square Footage Calculator free, and do I need an account?
It is completely free with no sign-up, no download and no usage limit. Everything is calculated in your browser, so the numbers you type never leave your device.
Results are estimates for general information. For medical, legal, structural or financial decisions, confirm with a qualified professional.