Methodology

Every planner on this site measures the same way. This page says how, and where it stops being reliable.

The drawing and the answer are the same thing

Most "will it fit" calculators work out an answer from your numbers and then draw a picture next to it. The two can drift apart, and the picture ends up decorative.

Here there is one set of geometry. When you drag a table, the table's new corners are what gets measured, and the verdict is written from that measurement. If the drawing shows the table touching the wall, the answer says it touches the wall. There is no second calculation that could disagree.

Footprint and clearance are counted separately

An object has two outlines. The solid one is what it physically occupies. The dashed one is the space around it you need kept free — chair pull-out, treadmill run-off, the arc a Murphy bed sweeps as it comes down.

They fail differently, so they are reported differently:

• The solid outline through a wall or another object is a hard no. Two things cannot be in the same place.
• The dashed outline short of its space is "tight". It means the arrangement works but is uncomfortable, and plenty of people live like that on purpose.

Which is why the verdict has three states rather than two.

The clearance numbers are yours

Wherever a planner needs a clearance, it asks you for it and shows you a default. The defaults are the figures the relevant trade normally quotes, listed on the sources page. None of them is a standard with force behind it, and a good number of them are argued about. Changing one changes the answer immediately, which is the point.

How shapes are handled

• Rectangles are exact, at any angle. Turning an object turns its four corners, and collisions are tested against the turned corners, not a box drawn round them.
• Round and oval objects are drawn and measured as a 32-sided outline. At furniture sizes that sits within about 2 mm of a true curve. Distances from an ellipse to a wall use the exact formula rather than the polygon, so a round table's wall gaps are not approximated at all.
• Everything is a plan view. Height is checked as a separate number where a tool needs it, not as part of the outline. Nothing here models a sloped ceiling, a bulkhead or a bay window.

Snapping and free placement

While you drag, an object pulls onto a wall, the middle of the room, or the edge of a neighbour when it comes within a few pixels. Turn the snap off and it goes exactly where you put it. Snapping only affects where things land; it never changes what gets measured afterwards.

Rounding

Measurements display to the nearest inch in feet-and-inches, or two decimal places in metres. The arithmetic underneath is done in metres at full precision — the rounding is only in what you read. Where a figure is genuinely uncertain, such as how many people a table seats, it is printed as a range.

What these planners do not know

• Skirting boards, architraves, radiators, pipe boxing and window sills.
• Doors, unless you add one as an exclusion zone.
• Anything structural: joists, lintels, wall build-up, fixing points.
• Whether two people can physically carry the thing along that path.
• Carpet depth, floor level changes and out-of-square rooms.

Rooms are assumed rectangular and square-cornered. Few are. If yours is out by an inch across its length, take an inch off before you type it in.

Corrections

If a number here is wrong, say so. Changes to any model get noted on this page.