You can't buy a partial box. Rounding down leaves you short mid-install — the worst place to be.

What about closets / hallways?

Add a small rectangle for each. Closets are typically 2×4 to 4×6 ft; standard hallways are 3 ft wide × length.

Are circles and triangles common in real rooms?

Circular: rotunda foyers, round bay windows. Triangular: under-stair landings, attic peaks, angled bay windows. Most builds skip both, but odd-shaped renovations use them.

How accurate does my measurement need to be?

Aim for ±2 inches (~0.17 ft). For a 12×14 room that's ±2 ft² out of 168 — well within the 10% waste buffer.

You can't buy a partial box. Rounding down leaves you short mid-install — the worst place to be.

What about closets / hallways?

Add a small rectangle for each. Closets are typically 2×4 to 4×6 ft; standard hallways are 3 ft wide × length.

Are circles and triangles common in real rooms?

Circular: rotunda foyers, round bay windows. Triangular: under-stair landings, attic peaks, angled bay windows. Most builds skip both, but odd-shaped renovations use them.

How accurate does my measurement need to be?

Aim for ±2 inches (~0.17 ft). For a 12×14 room that's ±2 ft² out of 168 — well within the 10% waste buffer.

Square Footage Calculator (multi-shape + flooring)

Add up areas from up to 4 rectangles, triangles, and circles, then size the flooring order with waste + cost.

Result

Total area (sum of shapes)

168.0 ft²

Order 184.8 ft² with 10% waste = 9 boxes ($831.6).

Rectangle 112 × 14 = 168.00 ft²
Rectangle 20 × 0 = 0.00 ft²
Triangle 1½ × 0 × 0 = 0.00 ft²
Circle 1π × (0/2)² = 0.00 ft²
Sum168.00 ft²
Order qty (with waste)184.80 ft²
Boxes needed (raw)8.213
Boxes to buy (rounded up)9
Flooring cost$831.6 @ $4.5/ft²

Step-by-step

Rect: L·W. Triangle: ½·B·H. Circle: π·r².
Sum = 168.00 + 0.00 + 0.00 + 0.00 = 168.00 ft².
Apply 10% waste: 168.00 × 1.10 = 184.80 ft².
Boxes = 184.80 / 22.5 = 8.21 → round up to 9.
Cost = 184.80 × $4.5 = $831.6.

How to use this calculator

Enter the L × W of each rectangle in your floor plan (set unused to 0).
Triangles: base × height ÷ 2 (the inputs do the divide-by-2 for you).
Circles: enter diameter (the inputs square the radius for you).
Box coverage: check the flooring label — laminate boxes are typically 20-25 ft².
Waste %: 10% is the default for straight patterns; bump to 15-20% for diagonals.

About this calculator

Most rooms aren't a perfect rectangle. This calculator lets you combine up to four shapes — two rectangles, a triangle, and a circle — to model an L-shaped great room, a rectangular living room plus a triangular bay window, a round breakfast nook, or any combination. Once you have the total square footage, the flooring estimate sizes the order with a waste buffer (10% is standard; raise to 15-20% for diagonal patterns or rooms with many cuts) and computes the box count and total cost at your price per ft². Set any unused shape to 0 — they drop out of the sum automatically.

Frequently asked

You always lose flooring to end-cuts, mistakes, and pattern matching. Industry standard: 10% for straight installs, 15% for diagonal patterns, 20% for herringbone or chevron. Carpet has less waste (~5-8%); tile and wood need more.