Floor Plan Calculators
Six floor plan calculators for the numbers you need before you draw: the size of a room, the floor area of a home, the shape a room of a given area could take, whether your furniture fits and how many people an office holds. Six more groups cover rooms and stairs, flooring and tile, paint, land and measurement, concrete and steel take-off, and building costs. The room calculators work in feet and inches or in meters and show both.
In this section
- Room Size CalculatorEnter a room’s width and length in feet or meters to get its floor area in sq ft and m² and its perimeter, then open that room in the floor plan editor.
- Square Footage CalculatorAdd up rectangles in square feet and square meters for a room or a whole plan: floor plan square footage, L-shapes included.
- Floor Area CalculatorList every room with its size to get each area and the total: the floor plan area calculator for a whole home.
- Room Dimension CalculatorFind a room’s width and length from the floor area you want plus a proportion such as 3:4, or plus one side you already know. Works in feet and meters.
- Furniture Layout PlannerEnter a room size, add furniture at the editor’s library sizes and pick a walkway gap to see overlaps and tight spots on a top-down plan. Free, in your browser.
- Office Space CalculatorWork out how much office space your team needs from headcount, desk sharing, meeting rooms and circulation, or how many desks and people an area holds.
- Floor & Room CalculatorsCalculators for room volume, wall area, carpet area, scale, clearances, stairs, ramps and corridors in metric and imperial, linked to the floor plan editor.
- Architecture & Measurement CalculatorsExact unit converters for feet, inches, meters, sq ft, m², square yards, gaj, acres and hectares, plus plot area, FAR/FSI, coverage and setback tools.
- Flooring & Tile CalculatorsWork out grout, tile adhesive, skirting and marble or granite slabs for your rooms, and total the cost of a new floor at your own prices, in metric or imperial.
- Paint & Wall CalculatorsWork out how much paint, wallpaper or plaster you need for your walls, with coverage, wastage and cost at your prices.
- Construction Cost Estimator for IndiaEstimate what a house costs to build in India. Pick a city, enter your own rates and get a Bill of Quantities with materials, labour, waste and GST.
- RCC Quantity Takeoff CalculatorsCalculate steel weight from bar bending schedules and concrete quantities for nominal mixes. Free RCC takeoff tools for construction estimation.
What each room calculator does
| You enter | You get | Opens in the editor as | |
|---|---|---|---|
| Room size calculator | Width and length | Area and perimeter, and how much floor a bed, sofa and dining table take | One rectangular room |
| Square footage calculator | Rectangles and L-shapes | Each area and the total, in sq ft and m² | Any one of the areas, L-shapes included |
| Floor area calculator | A list of named rooms | Each room’s area and share, and the total floor area | Any one room, with its name |
| Room dimension calculator | An area plus a proportion or one side | A width and a length | One rectangular room |
| Furniture layout planner | A room size, furniture and a walkway gap | A top-down layout with overlaps and tight gaps flagged | The room with your furniture in place |
From a number to a drawing
The calculators that work out a room size have a "Design this room" button. It opens the editor with a rectangular room of that width and length already drawn, in the units you used, so you can go straight on to doors, windows and furniture.
The calculations run in your browser and nothing you enter is sent anywhere. Most calculators forget your numbers when you leave; the construction cost estimator keeps its last inputs in this browser so you can come back to them.
Typing sizes
Every calculator has a Metric / Imperial switch, and your choice is remembered in this browser for the next calculator you open. A bare number is read as meters in metric and as feet in imperial, and you can type a size the way it is written on a tape: 4.2, 420 cm, 13' 9" or 165 in.
Before you calculate
Frequently asked questions
Which calculator do I need for an L-shaped room?
The square footage calculator. Enter the overall width and length and the notch missing from one corner, or add the room as two rectangles.
Do the calculators measure to the inside of the walls?
They use the sizes you type. Rooms in the editor are measured to the wall center lines, so a room opened from a calculator encloses your size on its center lines and its clear floor is about one wall thickness smaller.
Can I work out the area of a whole house?
Yes, with the floor area calculator: list every room and it adds them up. Once the plan is drawn in the editor, its area schedule gives the same room-by-room table for the drawing.
Is anything I type stored or sent anywhere?
Nothing is sent anywhere. Most calculators forget your numbers when you leave, and only the metric or imperial choice is remembered in this browser. The construction cost estimator also keeps its last inputs in this browser so you can come back to them.
Do the calculators work on a phone?
Yes, they run in a mobile browser, and the furniture planner’s pieces can be dragged with a finger. A larger screen makes the planner easier to read.
Ready to plan your space?
It is free, runs in your browser and needs no account. Projects are saved privately on this device.