7 Things You Can Measure With Your iPhone You Probably Don't Realize
AR measuring apps aren't just for "how long is this thing". Once you start looking, your phone replaces a half-dozen tools you didn't realize you needed.
Most people install an AR measuring app, measure one thing, and forget it's there. Which is a shame, the same app handles a bunch of measurements that traditional tools either can't do or do badly. Here are seven uses you probably haven't tried.
1. The angle of a sloped roof
Hard to do with a tape measure, you need to climb up there. With an iPhone, stand at the foot of the wall, point your camera up along the roofline, and use the angle tool. The AR protractor reads the roof's pitch in degrees without you leaving the ground.
Useful for: solar panel quotes (which require pitch within ±2°), DIY shingle replacement, comparing real pitch to what an estate agent claimed.
2. Whether your TV is mounted level
Hold the phone against the side of the TV, switch to bubble level mode. The reading tells you whether the TV is plumb to within 0.5 degrees. The standard wall-mount tolerance is ±2 degrees, if you're outside that, the TV will look slightly off no matter how carefully you tightened the bracket.
3. The height of a tree (or a building, or a person)
AR height measurement uses the ground plane as a reference. Stand on level ground, point the camera at the base of the tree, tap to anchor, then aim at the top and tap again. The app calculates the height from the angle and your phone's position.
Accuracy: ±5% on a 10 m tree, ±10% on a 30 m building. Good enough for "is this tree too tall for the power lines?" but not for engineering purposes.
4. The exact width of a parking spot before you back in
From outside the car, point the camera across the parking spot between the lane lines. Tap each line. Compare to your car's width (usually 1.8-2.0 m for most sedans, 2.0-2.2 m for SUVs). If the spot's clear width is under 2.4 m and you have a wider vehicle, skip it, you won't have door clearance.
5. Whether a picture frame is hanging straight
Press the phone flat against the bottom edge of the frame. Check bubble level. Most frames hang with one nail and a wire, they always drift slightly off-level over time. A 1-degree tilt looks intentionally crooked; the AR level catches it instantly.
6. The slope of your floor
Old houses settle. Floors slope. Place the phone flat on the floor in different rooms, the level reading tells you exactly how much each floor slopes from horizontal. A 1-degree tilt over a 5 m room is 9 cm of vertical drop, which is enough to make a ball roll. Anything over 2 degrees indicates structural issues worth a surveyor's opinion.
7. How long the queue is
A small absurdity but useful: hold the phone up at the front of the queue, switch to AR measure, tap the front person's feet and then the back person's feet. Now you know exactly how long the queue is and how long you'll wait (people typically advance at 30-40 cm/sec in a checkout line). Especially fun at airports.
Bonus: things you can also measure but probably shouldn't
- Your dog's height for ordering a custom harness, works, but the dog has to stand still
- The depth of a swimming pool from above the water surface, possible with LiDAR, fails at non-LiDAR (water has no AR features)
- How far the moon is, no. Don't try.
The point
An AR measuring app turns your phone into a tape measure, level, protractor, and laser distance meter at once. The traditional tools each cost €15-50 and live in a drawer. The app is free and lives in your pocket. The next time you'd reach for any of those tools, try the app first. After a few weeks, the drawer stays closed.