Floor plan maker

How to draw a floor plan with measurements

1. Measure each room at floor level, wall to wall, with a tape or a laser measure: the inside width and length, and for an L-shaped room each wall in turn. Skirting boards make a few millimetres of difference; ignore them.
2. Pick your units (m, cm or ft-in) and type the width and length, then tap Add room. The next room you type is placed against the right-hand wall of the last one, one wall thickness away, so rooms that share a wall line up. Drag a room to move it; it snaps to the grid.
3. For any other right-angled shape, tap Draw and tap the corners in order on the grid (10 cm, or 6 in in feet). Each wall is kept straight across or straight down, and its length shows as you drag. Tap the first corner again, or Close room, to finish.
4. Correct a wall by typing it: in Move, tap a wall's length label and type the measured length. Only the corner at the end of that wall moves, so the walls you already got right stay where they are.
5. Add doors, windows and openings: pick one and tap a wall. Drag it along the wall to where it is; tap it to type its width, flip the side it opens into or move its hinge.
6. Save: a PDF at a true scale to print (check the 5 cm or 2 in line with a ruler), a PNG to send, or an SVG to open in a drawing program.

What it cannot do

• It is a 2D sketch, not 3D, and not an architect's or surveyor's drawing. Do not use it for planning permission, building work or a sale's legal floor area; those need a measured survey.
• Walls are lines with one thickness for the whole plan. There is no structure, no stairs, no roof, no ceiling heights and no separate thickness for outside walls.
• It does not read a plan from a photo or a PDF. You type or draw the rooms yourself; tracing over a picture of a plan is coming.
• No furniture yet. Beds, sofas, tables and kitchen units at real sizes are coming next.
• Drawn rooms have right-angled corners. Typing a new wall length moves only the next corner, so that wall's neighbour can end up slanted; a curved wall or a bay window cannot be drawn.
• The PDF uses a standard font, so a room name in a script other than Western European letters prints with ? in place of those letters. The PNG and SVG keep them.

How the areas and the scale are worked out

Every length is kept in millimetres, whatever unit you see, and converted only for display: 1 in is exactly 25.4 mm, 1 ft is 304.8 mm and 1 sq ft is 0.09290304 m². So a 4 m wall reads 4.00 m, 400 cm or 13′ 1.48″ (157.48 in), and switching back and forth never moves a corner.

A room's area comes from its corners with the shoelace formula: add up x₁y₂ − x₂y₁ for each wall round the room and halve it. It gives the exact area of any outline whose walls do not cross, L-shapes and U-shapes included. A worked example: a room 6 m wide and 4 m long with a 2 × 2 m corner taken out (a chimney breast or a cupboard) has corners at (0, 0), (6, 0), (6, 2), (4, 2), (4, 4) and (0, 4); the formula gives 20.00 m² (215.28 sq ft), the same as 24 m² minus 4 m². Its inside perimeter, the length of skirting board it needs, is 20.00 m. Areas are inside areas, measured to the inner face of the walls, which is what flooring, paint and heating sums want.

A scale says how much smaller the paper is than the room. At 1:50 every 50 mm of room is 1 mm of paper, so a 4 × 3 m room prints as an 80 × 60 mm rectangle; at 1:100 it is 40 × 30 mm. The imperial scales are named the way US plans are: 1/4 in = 1 ft is 1:48 (that 4 m wall prints 83.3 mm, 3.28 in) and 1/8 in = 1 ft is 1:96. An A4 page at 1:50 holds a plan about 8.9 × 10.9 m including the walls when upright, or 13.2 × 6.6 m turned sideways; the page picks whichever fits. When the plan is too big for the page at your scale the tool says so and offers the next smaller scale rather than shrinking it quietly.

Questions

How do I draw a floor plan with measurements for free?

Measure each room wall to wall at floor level, then type its width and length here and tap Add room, or tap Draw and tap the corners on the grid. Every wall shows its length, each room shows its area and inside perimeter, and the total floor area is shown under the plan. Add doors and windows by tapping a wall, then save the plan as a PNG, an SVG or a PDF at a stated scale. There is no account and the plan is never uploaded.

How do I work out the area of an L-shaped room?

Draw its outline corner by corner and the tool adds up the area for you with the shoelace formula, which works for any outline whose walls do not cross. By hand, split it into two rectangles: a room 6 m by 4 m with a 2 m by 2 m corner missing is 6 × 2 = 12 m² plus 4 × 2 = 8 m², 20.00 m² in all. Its inside perimeter is 20.00 m, the same as the 6 × 4 m rectangle around it.

What does a scale of 1:50 or 1/4 inch to the foot mean?

At 1:50 one centimetre on paper is 50 cm in the room, so a 4 m wall is drawn 80 mm long and a 4 × 3 m room is an 80 × 60 mm rectangle. At 1/4 in = 1 ft a quarter inch on paper is one foot, which is 1:48. The PDF prints a scale bar and a 5 cm or 2 in check line; measure that line after printing, and if it is not exactly 5 cm or 2 in the printer scaled the page, so print again at 100 % or Actual size.

How do I convert room measurements between metres and feet?

One inch is exactly 25.4 mm, so one foot is 304.8 mm and one square foot is 0.09290304 m². A 4 m wall is 157.48 in, which is 13 ft 1.48 in; a 4 × 3 m room is 12.00 m² or 129.17 sq ft. In this tool every length is stored in millimetres, so switching between m, cm and ft-in any number of times never changes the plan.