How much extra flooring should I order for waste?

Most installers recommend adding 5–10% extra for straight, simple layouts and 10–15% for diagonal patterns, herringbone, or very cut‑heavy rooms. The exact percentage depends on the product and layout. This calculator lets you choose a waste margin and shows both the raw area and the adjusted flooring needed.

Can this floor plan calculator handle different units?

Yes. You can work in feet and inches or in meters and centimeters. The tool automatically converts between square feet and square meters, and you can switch units at any time. Each room uses the same unit system so your totals stay consistent.

How do I calculate an L-shaped or irregular room?

Break the room into simpler rectangles. For example, an L-shape can usually be split into two rectangles. Add each rectangle as a separate room or sub‑room in the calculator, enter its dimensions, and the tool will sum the areas. For very irregular shapes, you can approximate with more rectangles or use a polygon area tool.

What is the difference between floor area and flooring needed?

Floor area is the exact measured area of your rooms. Flooring needed is the floor area plus an allowance for waste due to cutting, pattern matching, and defects. The calculator shows both values so you can see how much material is actually required to complete the job.

Floor Plan Calculator – Room Area, Total Square Footage & Flooring

How this floor plan calculator works

This floor plan calculator is designed for homeowners, installers, architects, and real‑estate professionals who need a fast, accurate way to estimate room areas and flooring quantities. Unlike simple square footage tools, it supports:

Multiple rooms or sub‑rooms (for L‑shapes and irregular layouts)
Feet/inches or meters/centimeters input
Automatic ft² ⇄ m² conversion
Waste margin for cuts, patterns, and off‑cuts
Optional box/plank coverage to estimate boxes needed

Step 1 – Choose your unit system

Select whether you want to work in imperial (feet and inches) or metric (meters and centimeters). All room dimensions will use the same unit system so your totals stay consistent.

Step 2 – Add rooms and dimensions

For each room, enter a descriptive name (e.g., “Living room”, “Bedroom 2”, “Hallway”) and its length and width. The calculator automatically converts mixed units:

Imperial example

Length = 12 ft 6 in → \( 12 + \frac{6}{12} = 12.5 \) ft

Width = 10 ft 0 in → 10 ft

Area = \( 12.5 \times 10 = 125 \,\text{ft}^2 \)

Metric example

Length = 4 m 20 cm → \( 4 + \frac{20}{100} = 4.20 \) m

Width = 3 m 50 cm → \( 3 + \frac{50}{100} = 3.50 \) m

Area = \( 4.20 \times 3.50 = 14.7 \,\text{m}^2 \)

Step 3 – Handling L‑shaped and irregular rooms

For L‑shaped or irregular rooms, split the space into rectangles and add each as a separate room or sub‑room:

Sketch the room and draw rectangles that cover the full area without overlapping.
Measure each rectangle’s length and width.
Add each rectangle as its own row (e.g., “Living L‑shape A”, “Living L‑shape B”).
The calculator will sum all areas automatically.

Step 4 – Add a waste margin

Flooring projects always generate waste from off‑cuts, pattern matching, and damaged boards. A common rule of thumb:

5–10% waste for straight, simple layouts
10–15% waste for diagonal, herringbone, or complex layouts

Set your waste percentage in the calculator. The required flooring area is then:

\[ \text{Flooring needed} = \text{Measured area} \times \left(1 + \frac{\text{Waste \%}}{100}\right) \]

Step 5 – Estimate boxes or packs

If you know how many square feet or square meters each box of flooring covers, enter that value. The tool will divide the required area by coverage per box and round up to the next full box:

\[ \text{Boxes needed} = \left\lceil \frac{\text{Flooring needed}}{\text{Coverage per box}} \right\rceil \]

Common floor plan area formulas

Most residential and commercial rooms can be approximated with a few basic shapes:

Rectangle: \( A = \text{length} \times \text{width} \)
Square: \( A = \text{side}^2 \)
Right triangle (e.g., under stairs): \( A = \frac{1}{2} \times \text{base} \times \text{height} \)
Circle segment (e.g., bay window): approximate as a rectangle or triangle for flooring purposes.

FAQ

How do I calculate the square footage of a room?

Measure the length and width in the same unit (ft or m), then multiply them. For example, a 12 ft by 15 ft room is \( 12 \times 15 = 180 \,\text{ft}^2 \). If you measured in inches or centimeters, convert to feet or meters first.

What if my measurements are in inches or centimeters only?

You can either convert them manually or use the mixed unit fields. For example, 150 inches is \( 150 \div 12 = 12.5 \) ft. Similarly, 420 cm is \( 420 \div 100 = 4.2 \) m.

Should I include closets and hallways?

For flooring estimates, you usually do include closets, pantries, and hallways if they will receive the same flooring. Add them as separate small rooms so you can see their contribution to the total area.

Why are my totals slightly different from hand calculations?

The calculator keeps more decimal places internally and rounds only for display, so you may see small differences compared to hand‑rounded numbers. This is normal and usually works in your favor for ensuring enough material.

Can I print or save my floor plan calculations?

Yes. Use the Print summary button for a printer‑friendly version, or Copy text summary to paste the breakdown into an email, quote, or project notes.

Floor Plan Calculator

Floor plan & flooring estimator

Rooms

Totals

Measured floor area

Flooring needed (with waste)