Square Footage Calculator

Calculate total square footage for multiple rooms. Estimate renovation cost per square foot.

By Konstantin Iakovlev · Updated September 2026 · Source: HomeAdvisor

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Total Square Footage

468 sqft

Room-by-Room Breakdown

Living Room (20 \u00d7 15 ft)300 sqft
Bedroom (14 \u00d7 12 ft)168 sqft
Total468 sqft

Use the Square Footage Calculator above to calculate your results. Enter your values and see instant results — all calculations run in your browser.

Disclaimer: This calculator is for informational purposes only. Results are estimates from the numbers you enter and the assumptions described on this page; check them against local building codes, product specifications and current prices, and have structural, electrical or gas work designed or checked by a licensed professional.

How It Works

Getting an accurate total area for the rooms in your home is the foundation of any renovation budget. The number drives how much material you order, how labor is estimated, and how much room you leave in your overall spending plan. Knowing your true square footage before you commit to anything keeps a project on solid financial footing.

Each room you enter is measured on its own and then added to the running total. Each room is a rectangle, length times width. For an L-shaped or other irregular room, split it into rectangles and enter each one as its own room; the calculator has no triangle or circle shapes. To estimate renovation cost, the tool multiplies your total square footage by whatever cost-per-square-foot figure you supply.

Measuring twice before you order anything is the surest way to avoid the expense of buying too much or too little material. Odd spaces like bay windows and alcoves are easy to overlook, yet they add up. Treat any cost-per-square-foot figure as an average, since real prices swing with material grade, labor rates, and how involved the work is. Setting aside a contingency of 10-20% gives you cushion when surprises appear, as they usually do.

Example: Renovating a Living Room and Kitchen

  1. 1 You're planning to renovate your living room and kitchen. The living room measures 18 feet by 15 feet, and the kitchen is 12 feet by 10 feet. You've obtained quotes indicating an average renovation cost of $75 per square foot in your area for the scope of work you're considering.
  2. 2 Living Room: 18 ft * 15 ft = 270 sq ft. Kitchen: 12 ft * 10 ft = 120 sq ft. Total Square Footage: 270 sq ft + 120 sq ft = 390 sq ft. Estimated Renovation Cost: 390 sq ft * $75/sq ft = $29,250.
  3. 3 The total square footage for your living room and kitchen renovation is 390 square feet. Based on an average cost of $75 per square foot, your estimated renovation cost is $29,250.
  4. 4 This estimate provides a solid starting point for your budget. Remember to get detailed quotes from contractors that break down costs for materials, labor, and any specialized services to refine this figure further.

Source: HomeAdvisor · Last updated: September 2026

Frequently Asked Questions

How do I calculate the square footage of a room?
Measure the length and width of the room in feet and multiply them. For example, a 12-foot by 15-foot room is 180 square feet. For L-shaped rooms, divide into rectangles and add the areas.
What renovation cost per square foot should I enter?
Use the rate from quotes for your own job: divide a contractor's price by the square feet it covers. Per-square-foot prices vary with region, materials and scope far more than a single national average can show. The calculator has no built-in rate; the cost line appears only after you enter one.
Does a garage count in square footage?
Garages, unfinished basements, and attics are typically excluded from livable square footage in real estate listings. Only heated, finished spaces with a ceiling height of at least 7 feet count.