Square Footage Calculator
Calculate rectangular area with quantity and deductions.
How do I work out square footage?
Square footage is length multiplied by width for each rectangular area, added together.
Formula: Net area = length × width × quantity − deductions. Dimensions are converted to square feet.
Net square footage
120sq ft
- Gross area
- 120 sq ft
- Square metres
- 11.15 m²
- Assumption
- 1 equal rectangular area(s)
Results assume rectangular areas and exact entered dimensions.
What this calculator does
Find square feet and square metres from dimensions, repeated equal areas, and optional deductions.
Use it to turn Dimension unit, Length, Width, Number of equal areas, and the other shown inputs into a checked result you can compare, copy, or rerun with different assumptions.
The page shows the formula, a numeric worked example, and the assumptions that affect this home calculation.
Inputs and what they mean
- Dimension unit
- — choice value.
- Length
- — number value.
- Width
- — number value.
- Number of equal areas
- — number value.
- Total deduction
- — number value.
How to use it
- Enter the project dimensions and choose their unit.
- Adjust waste, coverage, quantity, and other assumptions.
- Use the rounded purchase estimate as a planning guide.
Formula
Net area = length × width × quantity − deductions. Dimensions are converted to square feet.
Inputs used: Dimension unit, Length, Width, Number of equal areas, Total deduction.
Edge handling: Length is required.; Length cannot be negative.; Length must be no more than 1000000000.; Width is required.; Width cannot be negative..
Worked example
Two 12 × 10 ft areas
- Start with Dimension unit: ft, Length: 12, Width: 10, Number of equal areas: 2, Total deduction: 0.
- Apply the method: Net area = length × width × quantity − deductions. Dimensions are converted to square feet.
- Gross area is 240 sq ft before deductions.
Reading the result
The headline figure is the main answer. Any breakdown underneath shows the parts that make it up, so you can check the working and see what changes when you adjust an input.
Limitations and assumptions
- This is a planning estimate based on your inputs and assumptions, not an exact contractor, installer, or supplier quote.
- Inputs outside the supported range are rejected rather than forced into a result.
- The result depends on the values you enter for this square footage calculator; it does not supply missing rates, rules, prices, dates, or assumptions for you.
Common questions
How do I work out square footage?
Square footage is length multiplied by width for each rectangular area, added together. Check the formula, example, and limitations on this page before using the result for a real home decision.
Can I combine different room sizes?
Calculate each different rectangle separately and add the results; quantity handles repeated equal areas. Check the formula, example, and limitations on this page before using the result for a real home decision.
What belongs in deductions?
Use the combined square footage of openings or excluded areas. Check the formula, example, and limitations on this page before using the result for a real home decision.
How do I use the Square Footage Calculator?
Enter the required values for Dimension unit, Length, Width, Number of equal areas, Total deduction. The calculator applies the formula on this page and shows the main result with any supporting breakdown so you can check the arithmetic.
What formula does the Square Footage Calculator use?
Net area = length × width × quantity − deductions. Dimensions are converted to square feet. The visible formula section above lists the calculation path and the edge cases the page handles, so the result can be checked without relying on the form alone.
Can the Square Footage Calculator be used for exact decisions?
Use it as a calculation aid, not as a substitute for checking the underlying rule, contract, policy, or professional advice that applies to your situation. When a result depends on local rules, personal details, prices, or dates, enter those values yourself and confirm them before acting.
Cite this page
Free Calculator. (n.d.). Square Footage Calculator. https://freecalculator.tech/tools/square-footage-calculator
"Square Footage Calculator." Free Calculator, https://freecalculator.tech/tools/square-footage-calculator.
Square Footage Calculator — Free Calculator, https://freecalculator.tech/tools/square-footage-calculator