Hanging a picture frame, installing a floating shelf, or leveling a wobbly table usually requires digging through a garage toolkit to find a physical bubble level. If you don’t own one, you might try to “eyeball it,” which almost always results in a crooked picture. Fortunately, your iPhone contains a highly accurate, built-in digital level hidden inside an app you probably forgot existed.
Where is the Level Tool?
Apple uses the iPhone’s internal gyroscope and accelerometer to measure tilt and orientation with incredible precision. For years, the level was hidden inside the Compass app. However, Apple recently moved it to a more logical location.
- Unlock your iPhone and search for the app named Measure. (This app is pre-installed on every modern iPhone; it has a black icon with a yellow and white ruler).
- Open the app. It will likely open to the augmented reality camera view.
- Look at the very bottom right corner of the screen and tap the tab labeled Level.
How to Use the Level Horizontally (Flat)
If you are trying to level a table, a desk, or a washing machine, you will use the horizontal mode.
- Place your iPhone flat on its back (screen facing the ceiling) directly onto the surface you want to measure.
- The screen will display two overlapping circles with a degree number in the center.
- As you tilt the surface, the circles will separate, and the degree number will increase, indicating how far off-level you are.
- Adjust the legs of your table or machine. As it gets closer to perfect, the circles will merge.
- When the surface is perfectly flat, the screen will instantly turn bright green and display 0°.
Note: For the most accurate reading, ensure your iPhone does not have a massive, bulky case that prevents it from lying perfectly flat. The protruding camera bump on modern iPhones is automatically accounted for by the software.
How to Use the Level Vertically (Walls and Pictures)
If you are hanging a picture frame or checking a door frame, you will use the vertical mode.
- Hold your iPhone upright (in portrait or landscape orientation).
- Press the side edge (or bottom edge) of the iPhone directly against the side or top of the picture frame you are hanging.
- The interface on the screen will change from circles to a horizontal line dividing two halves of the screen (resembling an artificial horizon on an airplane).
- Tilt the picture frame (and the phone against it) left or right.
- When the frame is perfectly straight, the line will snap to the center, the screen will turn bright green, and it will display 0°.