How to Measure Square Footage with Your iPhone
Length times width works fine — until the room has an alcove, a bay window, angled walls, or you're doing it alone with a sagging tape measure. A LiDAR scan measures the room as it actually is, and does the math for you.
What you need
An iPhone or iPad with a LiDAR sensor — that's the Pro models: iPhone 12 Pro and every Pro/Pro Max since, or an iPad Pro from 2020 onward (full list in our compatibility guide). LiDAR fires invisible laser pulses and times their reflections, measuring thousands of points per second — a tape measure that never sags and never needs a second person.
Scan the room
- Open RoomKit and start a Single Room scan (optimized for spaces under ~500 sq ft).
- Hold the phone up and walk the room slowly, sweeping the camera along each wall. You'll see walls, doors, windows and furniture snap into an outline in real time.
- Cover every wall and corner — including behind furniture where you can. The live preview shows what's been captured.
- Finish the scan. RoomKit builds the floor plan and computes the numbers.
Read the numbers
Open the project's details and you get the full measurement sheet, in feet or meters (Settings → units — Automatic follows your region):
- Surface area — the square footage you came for.
- Perimeter — wall length around the floor, i.e. your baseboard/trim number.
- Volume — floor area × ceiling height, useful for HVAC sizing and paint estimates.
- Counts — rooms, bedrooms, bathrooms, doors, windows, and detected objects.
The 2D plan itself shows wall-by-wall dimensions, so you can pull any single wall's length without re-measuring.
What it's good for: flooring and paint quantities, furniture planning, rental listings, storage estimates — anything with a waste margin or a tolerance measured in inches. For cut-to-size jobs (countertops, built-ins), treat the scan as the estimate and confirm final cuts with a tape. More in our accuracy guide.
Common square-footage jobs, faster
- Flooring: surface area + ~10% waste. One scan per room, add them up.
- Paint: perimeter × ceiling height − doors/windows ≈ wall area. The scan gives you all three inputs.
- Rent/list a room: scan once, quote the area, and export the plan as a PDF for the listing — see the real-estate guide.
- Whole house: Multi-Room mode (Pro) merges scans into one plan with per-room stats — the whole-house guide walks through it.
Measure your first room with RoomKit
Scan, read the square footage, export the plan. Free on LiDAR iPhones & iPads.
FAQ
Can my iPhone really measure a room by itself?
With LiDAR, yes — thousands of distance measurements per second, assembled into a measured floor plan.
Does square footage include closets and wall thickness?
RoomKit reports the scanned area including wall allowance; scan exactly the spaces you want counted.
Is a LiDAR scan accurate enough for buying flooring or paint?
Yes — you buy both with a waste margin. Confirm cut-to-size work with a tape.