If you examine our floor plans and calculate the room areas, the total may differ from what is printed. Why does this happen, and what is accurate? The answer is usually simple: not all rooms are rectangular.

When the floor plan shows room dimensions, it provides the maximum length and width, which may include alcoves or other irregularities. As a result, multiplying these dimensions can give an area larger than the room's actual usable space. For example:

You can see that the rectangle calculated from the maximum dimensions is larger than the room itself. The actual area, highlighted in green, is shown below. Red dots indicate the room’s various angles, showing the true shape and size:

​

This illustrates why dimensions can be deceptive in non-rectangular rooms; therefore, always consider the shape of the room.

If math isn’t your thing, now’s your chance to look away! Our software handles all calculations for you, using the coordinates of key points (like the red dots above) to define the area accurately.

The type of algorithm used is described on this Wikipedia page.

Also, remember that some rooms can be excluded from the total area with rules depending on the chosen method: