MiniCalci

Calculators & Converters
Construction & DIY

Square Footage Calculator

Free square footage calculator adds up multiple rooms into a total square footage. Enter each room's length and width to calculate combined area in sq ft and sq meters.

Add a row for each room, then enter its length and width in feet

What Does This Square Footage Calculator Do?

This square footage calculator lets you add multiple rooms or areas, each with its own length and width, and automatically totals them into one combined square footage. It's built for situations where you need a whole-house or multi-room total — like ordering flooring, estimating paint, or listing a property's total living area — rather than just one room at a time.

The Square Footage Formula

Square footage for a rectangular room is simply length multiplied by width, both measured in feet. To find a total across multiple rooms, calculate each room individually and add the results together.

Room Sq Ft = Length (ft) x Width (ft)
Total Sq Ft = Sum of all Room Sq Ft values
Total Sq M = Total Sq Ft x 0.092903

Worked Example: Living Room + Bedroom

Say you're totaling square footage for two rooms getting new flooring:

  • Living Room: 15 ft x 12 ft = 180 sq ft
  • Bedroom: 12 ft x 10 ft = 120 sq ft
  • Total = 180 + 120 = 300 sq ft
  • In square meters: 300 x 0.092903 = ~27.87 sq m

Why Square Meters Too?

While the US primarily uses square feet for home measurements, square meters are the standard unit in most of the rest of the world. Showing both is useful if you're working with international flooring products, comparing listings across countries, or simply need the metric conversion for a spec sheet.

Practical DIY Tips for Measuring Square Footage

  1. Measure wall to wall, not furniture to furniture: Get the actual room dimensions at floor level, ignoring baseboards and trim depth for a quick estimate.
  2. Break up irregular rooms: Split L-shaped or oddly angled rooms into two or more rectangular sections, measure each separately, and add them as separate rows.
  3. Add extra for flooring waste: Most flooring installers recommend ordering 5-10% more material than your calculated total to cover cuts, pattern matching, and mistakes.
  4. Double-check with a second measurement: Measure each room twice (e.g. at different points along a wall) if the room isn't a perfect rectangle, and use the larger measurement to avoid running short on materials.
  5. Keep a saved list: If you're re-measuring for multiple projects (paint, flooring, HVAC sizing), keep your room-by-room breakdown handy since you'll likely need the same numbers more than once.
  6. Know what counts toward "livable" square footage: For real estate purposes, only finished, heated, enclosed space typically counts — garages, unfinished basements, and porches are usually excluded.

Planning flooring, paint, or other room-based projects? Check out our paint calculator to figure out how much paint your total square footage will need, or our concrete calculator for outdoor slabs and patios.

Frequently Asked Questions

How do I calculate the square footage of a house?
Measure the length and width (in feet) of each room, hallway, and enclosed area, multiply length by width for each room's square footage, then add all the individual room totals together for the whole house's square footage.
Is there a square footage calculator for multiple rooms?
Yes, this calculator lets you add a row for each room with its length and width, calculates each room's individual square footage, and sums them into one running total — useful for flooring, painting, or listing a home's total living area.
How do I convert square feet to square meters?
Multiply the square footage by 0.092903 to get square meters. For example, 300 sq ft x 0.092903 = about 27.87 square meters. This calculator shows both units automatically.
How do I measure square footage for flooring?
Measure the length and width of each room in feet, multiply to get each room's square footage, then add up all rooms getting new flooring. Most flooring installers recommend adding 5-10% extra to your total to account for cuts, waste, and pattern matching.
Do closets and hallways count toward square footage?
For most real estate and flooring purposes, yes — any enclosed, finished, heated living space counts, including closets and hallways. Unfinished basements, garages, and porches are typically excluded from a home's official listed square footage.
What's the difference between square footage and square yardage?
Square yardage is used mainly for carpet and flooring materials sold by the square yard. To convert, divide your total square footage by 9 (since 1 square yard = 9 square feet).
How accurate does my room measurement need to be?
For most DIY purposes (flooring, paint, furniture planning), measuring to the nearest inch or half-inch is sufficient. For anything with legal or financial implications (real estate listings, permits), consider having a professional appraiser or contractor measure and verify.
Can I use this calculator for irregularly shaped rooms?
Yes — split an irregular room (like an L-shaped living room) into two or more rectangular sections, add each section as its own row, and the calculator will sum them into one total square footage for the space.

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How this is calculated: This tool uses standard, well-established formulas for construction & diy calculations. Results are estimates for informational and planning purposes — always double-check figures for anything with real-world consequences (e.g. ordering materials or submitting grades).