Square Footage Calculators — Pick the Right Tool for Your Project
FootyCalc is a hub of free, specialised square footage tools. Use the quick calculator for rectangle rooms below, or jump to the scenario-specific calculator that fits your project — flooring, paint, tile, roofing, land, or whole-house.
Need every shape in one place? Open the full Square Footage Calculator for circles, triangles, trapezoids, L-shapes, and irregular rooms.
Last updated:Quick rectangle square footage calculator
Not a rectangle? Use the full seven-shape calculator for circles, triangles, trapezoids, L-shapes, irregular rooms, and multi-room totals.
Specialized Square Footage Calculators
FootyCalc is organised around your use case. Each calculator below is tuned for one project with the right units, waste factor, and industry rules baked in.
Main Calculator
All seven shapes with waste factor, cost, and visualization.
Room Calculator
Dedicated tool for bedrooms, kitchens, and living rooms.
House Calculator
Whole-home total following the ANSI Z765 standard.
Flooring Calculator
Hardwood, vinyl, and laminate with 10% waste factor.
Tile Calculator
Tile counts and box quantities with pattern waste.
Carpet Calculator
Square yards from sq ft with padding included.
Paint Calculator
Gallons per wall at 350 sq ft coverage.
Roof Calculator
Shingle squares and pitched-roof adjustments.
Cost per Sq Ft
Two-way converter for budgeting renovations.
Guides: Learn the Math Behind Square Footage
If you'd rather understand the formulas and measurement tricks than just click a tool, start with these plain-English guides.
How to Calculate Square Feet
Step-by-step guide for every shape, with worked examples.
Square Feet Formulas
Full formula reference for rectangles, circles, triangles, and L-shapes.
Inches & Feet to Sq Ft
Convert feet-and-inch tape readings to clean square footage.
Sq Ft vs Linear Feet
When to measure by area and when to measure by length.
Sq Ft vs Cubic Feet
Use area for flooring, volume for mulch, concrete, and HVAC.
Price per Square Foot
How real-estate, flooring, and renovation cost-per-sqft is calculated.
How Many Square Feet Is My Room?
Check the most searched room dimensions. Every size links to a dedicated page with unit conversions, typical uses, and related tools.
How many square feet is a 10x10 room?
100 sq ft — small bedroom, home office, flooring & paint estimates.
10×1210 × 12 = 120 sq ft
Standard bedroom.
12×12How much flooring for a 12x12 room?
144 sq ft — dining or guest room with waste & cost tables.
12×1512 × 15 = 180 sq ft
Small master bedroom.
14×1614 × 16 = 224 sq ft
Mid-size living room.
15×2015 × 20 = 300 sq ft
Large living room.
16×2016 × 20 = 320 sq ft
Large master suite.
20×2020 × 20 = 400 sq ft
Great room, two-car garage.
AllBrowse all sizes
See 60+ room dimensions with notes.
- How many square feet is a 10x10 room?
- How to calculate square feet for flooring
- How much flooring do I need for a 12x12 room?
- Square feet to square yards for carpet
- Cost per square foot to build a house (2026)
- How many gallons of paint for a 10x10 room?
Unit Conversions at a Glance
| From | To | Formula |
|---|---|---|
| sq ft | sq m | × 0.092903 (tool) |
| sq ft | sq yd | ÷ 9 (tool) |
| sq ft | acres | ÷ 43,560 (tool) |
| sq m | sq ft | × 10.7639 (tool) |
| acres | sq ft | × 43,560 (tool) |
| sq ft | sq in | × 144 (tool) |
Why Trust This SqFt Calculator
- Formulas verified against the ANSI Z765 home measurement standard and the US National Institute of Standards and Technology (NIST) conversion factors.
- No data leaves your browser. Every calculation is pure JavaScript running locally.
- Mobile-first. All inputs are at least 48×48 px and the result updates instantly as you type.
- Accessible. Full keyboard navigation, ARIA labels, and WCAG AA color contrast.
Frequently Asked Questions
How do I calculate square footage?
For a rectangular room, multiply length × width in feet. A 12 ft × 10 ft room is 120 sq ft. For other shapes, pick the matching tab in the calculator above — circle, triangle, trapezoid, L-shape, and irregular rooms all use their own geometry formulas.
What is a square foot?
A square foot (sq ft or ft²) is the area of a square with 1-foot (12-inch) sides. One square foot equals 144 square inches, 0.0929 square meters, or about 0.1111 square yards.
Is this sqft calculator free?
Yes. Every calculator on this site is free, requires no sign-up, and has no ads inside the tool itself. Your measurements never leave your device because all math runs in your browser.
Which calculator should I use for my project?
Use the quick calculator at the top of this page for rectangle rooms. Open the full Square Footage Calculator for circles, triangles, trapezoids, L-shapes, and irregular rooms. For project-specific buying, switch to a scenario calculator (Flooring, Tile, Carpet, Paint, Roof, or Cost per Sq Ft) so waste factors and material rules are baked in for you.
How accurate is the result?
The calculator uses exact geometry formulas and IEEE-754 double-precision math. The only source of error is your own measurements — typical tape-measure error is roughly ±0.5 inch, so expect practical accuracy within ±1%.
Does it work offline?
Once the page loads, yes — the calculator runs entirely client-side. You can even save the page with browser File → Save, then open the HTML file offline and keep using it.
Can I use inches, meters, or centimeters?
Yes. Each dimension input has a unit selector (ft, in, yd, m, cm). The calculator converts every input to feet before multiplying, so you can mix units across fields if needed.
What if my room has an alcove or cut-out?
Switch to L-shape if the room has one rectangular bump, or Irregular if it has several. You can add as many sub-rectangles as you need; the total updates instantly.