How to Measure a Room and Order the Right Amount of Flooring
Ordering flooring looks like a one-line calculation, area divided by box coverage, but a few details decide whether the order is right: how the room is measured, how much is lost to cuts, and the fact that boxes cannot be split. A room that is 5% short usually means a second order, and the second order may come from a different production run.
This guide covers laminate, vinyl plank, engineered wood and similar boxed flooring. The same method works for carpet and sheet vinyl, with the extra step of planning around the roll width.
Measure the room in sections
Walls are rarely perfectly straight or square, so measure the length and width at more than one place and use the larger figures. If a room is not a simple rectangle, split it into rectangles, find each area and add them up.
- Include closets, alcoves and bay recesses as their own rectangles.
- Include the floor space that door openings and doorways cover, since the flooring runs through them.
- Leave out areas you will not floor, such as a fixed kitchen island or built-in cabinets, only if your installer confirms the flooring will not run underneath.
Tape measures read in feet and inches, but the arithmetic needs a single unit. Convert the inches to a decimal by dividing by 12. A wall of 13 ft 8 in is 13 + 8 ÷ 12 = 13.67 ft, and one of 11 ft 4 in is 11.33 ft. Multiplied together, 13.67 × 11.33 gives about 154.9 ft². Writing the measurements on a sketch of the room, with each section labelled, prevents a missing piece when you add everything up.
Worked example: a living room measures 14 ft by 18 ft, giving 14 × 18 = 252 ft². A closet off one side is 3 ft by 4 ft, which adds 12 ft². The total floor area is 264 ft². To combine more complex outlines, see our guide on finding the area of an irregular room.
Add a waste allowance
Planks and tiles must be cut at walls and around obstacles, and some cut pieces cannot be reused. Damaged boards and awkward end pieces add to the loss. Common planning figures are:
| Layout | Typical allowance |
|---|---|
| Straight lay, simple room | 5% to 10% |
| Diagonal lay | 10% to 15% |
| Herringbone or intricate patterns | 15% or more |
order area = floor area × (1 + allowance)
With 264 ft² and a 10% allowance, the order area is 264 × 1.10 = 290.4 ft². A room with many corners, angled walls or stair nosings is a good candidate for the upper end of the range.
Round up to whole boxes
The box label states how many square feet (or square metres) each carton covers. Divide your order area by that number and always round up.
Suppose each box covers 20 ft². Then 290.4 ÷ 20 = 14.52, so you buy 15 boxes, which covers 300 ft². The extra 9.6 ft² beyond your calculated need is not wasted: it is a small reserve for repairs.
If boxes hold odd areas such as 23.4 ft², the same steps apply. Because the rounding can add a lot, check both the percentage you are adding and the real number of boxes. A closer look at those percentages is in our article on waste allowances for building materials.
Metric rooms work the same way. An 18 m² room with a 10% allowance needs 19.8 m². With boxes of 2.4 m², 19.8 ÷ 2.4 = 8.25, so you need 9 boxes. Use the area unit converter to translate between square feet and square metres.
Before you buy
- Buy all boxes at once and check that they share the same batch or lot number, since colour and finish can vary slightly between production runs.
- Keep one or two spare boxes, unopened, in case a section needs replacing later and the style has been discontinued.
- Follow the manufacturer's instructions for storing or acclimatising planks before installation.
- Underlay is sold by its own area per roll, so calculate it from the same floor area with its own waste figure.
- Carpet and sheet vinyl come in rolls of fixed width, so a room that is slightly wider than the roll may need a seam and extra length. Sketch the layout before ordering.
For a quick sanity check of the total area, use the square footage calculator or the area of a rectangle calculator.
- Square Footage Calculator: Type in the width and length of a room, or of the two sections of an L-shaped one, and get its area in square feet or any other unit. Add a price per square unit to see what flooring, paint or tile would cost.
- Area of a Rectangle Calculator: Enter the width and length, choose a unit and read the area in square units straight away. Below you will find the formula, worked examples and the mistakes to avoid.
- Area Converter: Pick a unit on each side, type an area and the converted value appears straight away. The guide lists the exact size of every unit in square meters, with worked examples and the mistakes to avoid.
This article is general information, not professional advice. See our Disclaimer and Editorial Policy.
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