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Square footage from a phone scan, and which number you should actually price off
Getting square footage out of a phone is the easy part now. The part nobody writes about is that a remodel is not priced off one square footage figure, and the scan will happily hand you the wrong one.
Two scans free. No card.
What ranks for this, and who it is written for
Page one is how to measure square footage with your phone, free apps that measure square footage, seven mobile measurement apps, a calculator, and an app store listing. Useful if you are a homeowner working out whether a rug fits. One result goes further and sells square footage from a single photograph, which is a claim worth being careful around.
None of it is written for somebody about to put a price on the room. That is the gap, and it is not about accuracy. It is about which figure you take out of the scan and what you do with it.
A room does not have one square footage
Ask a homeowner the square footage of her bathroom and you get one number, the floor. Price the bathroom off that one number and you will be wrong on most of the job, because almost nothing in a bathroom is sold by floor area.
Tile on the walls is wall area, minus the window and the door and the niche. Baseboard and crown are perimeter, minus the door openings. Paint is wall area plus ceiling, and whether you count the closet changes it. Flooring is floor area plus waste, and the waste depends on the pattern and which way the boards run.
A scan can give you all of those. The mistake is reading the one big number off the summary screen and quoting from it, which is exactly what a figure labelled square footage invites you to do.
Three numbers that decide the money
Floor area, and what it includes
This is the number everybody means by square footage. Check what it swept in. Under the vanity and the tub footprint are usually inside the boundary even though you are not tiling them. The closet may be in or out. On a kitchen, the area under the cabinet run is floor area you are not flooring.
Wall area once the openings come out
The one that moves a tile job most and the one most likely to be reported as a gross figure. A bathroom with a window and a door can lose 30 or 40 square feet to openings. Take them out yourself and you have the quantity you actually buy.
Perimeter, and how many breaks are in it
Baseboard, shoe, crown and the cut count all live here. A long rectangle and a room with four jogs can have the same perimeter and nothing like the same labor. The scan gives you the length. You still have to look at the shape.
Where a scan quietly disagrees with you
None of these are failures of the sensor. They are places where the scan drew a reasonable boundary and you would have drawn a different one, so they are worth a glance every time before the number turns into a price.
- A walk-in closet counted as part of the room, or counted as its own
- A bay window or bump out included at floor level but not in wall area
- Toe kicks and the space behind an appliance that you will never finish
- A chase or a boxed soffit read as a wall, which shortens your run
- An open doorway with no door, which is a gap in your baseboard and not a wall
- Sloped ceilings, where the floor figure is right and the wall figure is a guess
What the scan decides and what you still do
| What the scan gives you | What you still decide | |
|---|---|---|
| Floor area on a square room | A figure you can buy material from | Your waste factor, and which way the boards run |
| Wall area | Gross area and the openings it found | Whether every opening actually came out of it |
| Perimeter | Total length of the run | The cut count, which is shape and not length |
| A sloped or vaulted ceiling | A reliable floor figure | The wall and paint quantity, by eye |
| Cabinet runs | A plan view you can read linear feet off | Which runs you are actually replacing |
| Anything behind the plaster | Nothing. No phone sees through a wall. | Whether that alone is worth the drive |
On a phone without LiDAR there is no scan at all. The fallback is photographs plus room sizes the homeowner types in, and typed sizes get treated as typed sizes.
Questions contractors ask
How accurate is a phone scan for square footage?
On a normal room with LiDAR it is close enough to buy material from with your usual waste factor, which is the test that matters on a remodel. It is not a survey instrument. The thing that burns people is not the tolerance, it is pricing off the wrong figure.
Can it get square footage from a photograph?
No, and be wary of anything that says it can. Photographs tell you condition, materials and what is in the way. Dimensions come from the LiDAR capture, or from sizes somebody types in.
Does the scan give me wall area or just floor?
Both, plus perimeter and ceiling. The point of this page is that those are different numbers and the job uses all of them.
What about waste?
That stays yours. Waste is a decision about pattern, direction and how much of a box you are willing to eat, and it belongs in your own cost book rather than in a scan.
Who holds the phone?
Either of you. Your crew can capture a job on site, which is not metered on any plan, or you send the homeowner a link and she walks her own room with nothing to install.
What does it cost to try?
Two scans free with no card. Solo is 79 dollars a month for one user and 20 scans, Crew is 149 for five users and 60, Shop is 349 for unlimited users and 200. Extra scans are 4 dollars each.
Scan a room you already know
The fastest way to settle this is to scan a room you have already measured and priced, then put the figures side by side. Two scans free, no card, so the test costs you ten minutes.