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Can I measure a sofa in IKEA with an iPhone?

Yes, if the phone has LiDAR. Then you can scan the piece on the spot and get width, depth and height without a tape measure, without asking a member of staff, and without writing numbers on a slip of paper you will lose again.

Why furniture measurements are hard to take in a store

You're standing in the middle of a showroom. The sofa is pushed up against three other pieces that aren't yours. You don't have a tape measure with you, and even if you did, you'd have to crawl around cushions and armrests to get a figure you can trust. Spec labels on showroom furniture are often imprecise or missing entirely for the exact model in front of you — especially if it's set up as a display with no price tag beside it.

That's precisely the situation a phone with distance sensing solves: you don't have to clear space or find a colleague to hold the other end of the tape.

What LiDAR is, and why it matters here

LiDAR stands for "Light Detection and Ranging" — a small laser sensor that sends out light and measures how long it takes to come back. The result is a distance to every point the phone points at, many times a second. That's a completely different technology from the camera's ordinary image, which only captures colours and shapes with no depth.

Without LiDAR, an app can estimate distances from how objects move in the frame as you move the phone (called photogrammetry). That works for rough estimates, but is far less reliable than a direct distance reading — especially on a piece of furniture with soft edges like a sofa.

Which iPhone models have LiDAR

LiDAR is only fitted in the Pro models of iPhone (from iPhone 12 Pro onward) and in iPad Pro models with the same sensor. A regular iPhone or a cheaper iPad doesn't have it, no matter how new it is. If you're unsure about your own phone, the quickest test is to open a scanner app that uses LiDAR — if the sensor isn't there, the app refuses to start rather than hand you an inaccurate result.

How a furniture scan works in practice

• Walk around the piece. Most scanner apps ask you to move the phone around the object so every side gets captured — not just the front.
• Keep a good distance. Roughly a metre from the piece usually gives the best result. Too close, and the sensor loses the overview.
• Avoid moving too fast. The scanner builds the geometry up gradually — a quick, jerky motion leaves gaps in the model.
• Let the app find the edges itself. Most furniture scanners recognise the shape automatically and place a box around it, which you can then adjust.

How accurate are the measurements

On an ordinary piece of furniture like a sofa, a table or a cabinet, a LiDAR scan typically comes within a few centimetres of the true measurement — enough to tell whether the piece fits the room, and whether it will get through the door. It isn't cabinetmaker precision, but it's far better than eyeballing it, and faster than digging out a tape measure in the middle of a busy store.

Accuracy drops on fine detail: a slender table leg, a rounded corner edge, or fabric with deep folds. Here the scanner often sees a softer, more rounded shape than the sharp edge that's actually there. If you need a measurement down to the millimetre — for instance, to decide whether a sofa will just barely fit between two walls — a physical tape measure is still the safe choice for that one, critical measurement.

What can go wrong during a scan

• Glass and mirrors. A glass tabletop on a coffee table reflects the laser or lets it pass straight through — the scanner often sees nothing where the glass is.
• Glossy and shiny surfaces. Varnished wood or polished metal can produce noise in the reading for the same reason.
• Furniture packed close together. If the sofa is wedged between two other pieces, the scanner can struggle to see where one ends and the next begins.
• Poor lighting. LiDAR doesn't depend on light the way a camera does, but a very dark room can still make it hard for the app to track where the phone is moving.

Alternatives if the phone has no LiDAR

If you don't have a Pro model, you're not entirely stuck. Stores usually publish dimensions in their product catalogue or on the website — ask for the item number and look it up. An old-fashioned tape measure is still the most reliable tool you can carry regardless of phone. And a simple photo-with-an-object-for-scale (lay an A4 sheet next to the piece, for example, before you take the picture) gives you something to measure against afterwards, even without any app at all.

What HouseSense does

HouseSense has a short furniture scan, where you scan a single piece with LiDAR, and width, depth and height are added to your furniture library with one tap — ready to be dragged onto your own floor plan afterwards, so you can see whether the sofa actually fits the living room before you order it. The feature requires an iPhone or iPad with LiDAR; without one, furniture can instead be added by typing the dimensions in manually.

Can you trust the numbers to book a moving van or check a door width

For deciding whether the piece will roughly fit the room — yes. For deciding whether a sofa can just squeeze through a 77 cm door when the sofa itself measures 78 cm in width — no. The margin is too thin there for a scan's few-centimetre uncertainty to be safe. In that kind of tight case: measure both the piece and the door's clear opening with a tape measure, and add at least 3-5 cm of safety margin for turning and angling the piece along the way.

A worked example: does the sofa fit the alcove

You scan a sofa at 2.34 m wide. The alcove in the living room, which you've measured yourself with a tape, is 2.40 m. On paper there's 6 cm to spare — but the scan's uncertainty can easily run 2-3 cm either way on a soft piece like a sofa. In reality, then, you only know the width within a range of roughly 2.31 to 2.37 m. There's still room, but the margin is thinner than the 6 cm on paper suggests. If the margin is under 5 cm, ask the store for the official figure from the catalogue as a cross-check, or bring a tape measure back to the piece.

Decision: scan, measure or look up

1. Do you have a Pro iPhone or iPad Pro? Scan the piece — it's fastest and gives a usable estimate right away.
2. Is the measurement critical to whether something fits at all — a doorway, a tight alcove? Double-check with a physical tape measure regardless of what the scanner says.
3. Does the piece have glass, mirror or very glossy surfaces? Don't trust the scan of that part — measure it with a tape.
4. No LiDAR phone at hand? Look up the item number with the retailer, or ask for a measurement on the spot.