To calculate the square metres of a floor, multiply the length by the width of each room and add up the results. To know how much material to buy, add an allowance of between 5% and 12% depending on the type of floor and round up to full boxes. The calculator does it for you:
Square metre and flooring box calculator
Measure each room in metres (length × width). You can use a comma or a full stop for decimals.
Measured area 0 m²
With material allowance 0 m²
Boxes to buy 0
This is an estimate to guide you. The exact quantity depends on the plank format and the layout of the home: we measure it at no obligation during the visit.
How to calculate the square metres of a room
The formula is length × width = m², with both measurements in metres. A room measuring 4.5 m by 3.2 m has 4.5 × 3.2 = 14.4 m².
- Measure in metres or convert before multiplying: 350 cm is 3.5 m.
- Measure each room separately and add them together, without forgetting hallways, the entrance hall, the dressing room and wardrobes open down to the floor.
- Measure each wall at two or three points and keep the largest measurement: in older houses the walls are rarely parallel.
L-shaped or irregular rooms
Divide the room into rectangles, calculate each one and add them up. For example, an area of 4 × 3 m and a recess of 2 × 1.5 m: 12 + 3 = 15 m².
With columns or pillars
Calculate the whole room and subtract the area of each pillar (length × width of its base). In the calculator you can enter it under "Area to subtract".
How much flooring to buy: the material allowance
Never buy the exact square metres: cuts at walls, doors and corners create offcuts, and if you run out of material halfway through the job, a new batch may not have the same shade. As a guide:
| Floor type and laying pattern | Approximate allowance |
|---|---|
| Click laminate or vinyl, straight lay | 5–10% |
| Floating floor, straight lay | 8–10% |
| Wood parquet | 10–12% |
| Herringbone, diagonal or rooms with lots of cuts | More than for a straight lay |
Then round up to full boxes: divide the square metres including the allowance by the square metres in each box (shown on the packaging) and round up. Example: 48.8 m² of floating floor + 10% = 53.68 m²; with 2.22 m² boxes, you need 25 boxes (55.5 m²).
Keep any leftover boards: if one gets damaged one day, you will have pieces from the same batch to replace it.
How to calculate the square metres of a wall
For wall coverings (panelling, vinyl, panels), multiply the width by the height and subtract doors and windows. A 4 × 2.5 m wall with a 1.5 × 1 m window: 10 − 1.5 = 8.5 m².
Most common measuring mistakes
- Multiplying metres by centimetres without converting.
- Measuring just one wall and assuming the room is a perfect rectangle.
- Forgetting hallways, entrance halls and wardrobes.
- Buying the exact square metres, with no allowance.
- Not taking the laying direction into account: it changes the number of cuts (see which direction to lay a floating floor).
Frequently asked questions
How many extra square metres should I buy?
Between 5% and 12% depending on the floor: less for laminate or vinyl laid straight, more for parquet and for herringbone or diagonal patterns. Then round up to full boxes.
Do built-in wardrobes need to be measured?
If the floor is going to go inside the wardrobe, yes. If the wardrobe has a fixed base that won't be touched, no.
What happens if I buy less flooring than I need?
The job stops until more material is found, and the new batch may have a slight difference in shade.
How do you calculate the square metres of a terrace?
The same as an indoor floor: length by width, dividing it into rectangles if it is irregular. Outdoors it is also worth checking slopes and drains before choosing the floor (see the best outdoor flooring).
If you are replacing your floor with Payresa, you don't need to measure it yourself: on the visit we measure the home, calculate the material according to the model and the laying direction, and the quote is fixed and in writing.