Bubble Level

Precise bubble level, inclinometer & plumb bob: calibrate, measure, build right.

Turn your phone into a precision leveling tool. Bubble Level offers three measurement modes in one app — everything you need for construction, DIY, hanging pictures, or checking if your desk is truly flat.

▸ THREE MEASUREMENT MODES

• Level — A classic dual-axis bubble level. Watch the bubble float across a circular grid as you tilt your device. When the surface is perfectly flat, the bubble turns green and snaps to center. Displays real-time X (roll) and Y (pitch) angles.

• Angle — A digital protractor and inclinometer with a rotating needle and linear bubble bar. Measure any angle from 0° to 180° with 0.1° precision. Set a reference angle to track deviation from your target — perfect for matching slopes or repeating cuts.

• Plumb — A virtual plumb bob that shows vertical alignment. The animated bob swings to indicate tilt direction and magnitude. Ideal for checking door frames, posts, and walls.

Swipe between modes or tap the tabs at the top. It's that simple.

▸ CALIBRATION FOR TRUE ACCURACY

No two phone sensors are identical. Bubble Level includes a built-in calibration system that collects sensor samples over 3 seconds to eliminate device-specific drift. Place your phone on a known flat surface, tap Calibrate, and you're set. Calibration data is saved automatically and applied every time you open the app.

▸ REAL-TIME FEEDBACK

• Haptic — A short vibration pulse the moment your surface hits level or your target angle is reached. You can feel it without looking at the screen.
• Audio — An optional beep that sounds alongside the vibration. Great in noisy environments where you might miss the haptic cue.
• Visual — The bubble, needle, and plumb bob all shift to green when you're within the threshold.

Toggle vibration and sound independently in Settings.

▸ ADJUSTABLE SENSITIVITY

Set your level threshold anywhere from ±0.1° to ±2.0° in 0.1° steps. Tighten it for precision work or loosen it for quick checks. The default ±0.5° works well for most tasks.

▸ DESIGNED FOR THE JOB SITE

• Keep Screen On — Prevents your display from dimming while you work.
• Portrait lock — Consistent orientation so the UI never flips mid-measurement.
• Display rotation compensation — Accurate readings regardless of how your device reports screen rotation, including foldable phones.
• No sensor? No crash — The app detects missing hardware and shows a clear message instead of failing silently.

▸ CLEAN, MODERN INTERFACE

Built with Material Design 3. Supports system light and dark themes, or force your preference in Settings. Angle readouts use a monospace font for rock-steady digits. Animations run at 60 fps for a smooth, responsive feel.

▸ ACCESSIBILITY

Every visual element — the bubble, the protractor needle, the plumb bob — carries a content description so screen readers can announce the current angle. Status indicators never rely on color alone.

▸ REMOVE ADS

Bubble Level is free with non-intrusive banner ads. A single one-time purchase removes all ads permanently. Your purchase syncs across devices through Google Play and restores automatically on reinstall.

▸ AUTOMATIC UPDATES

The app checks for new versions on launch. Minor updates are offered as a suggestion; major updates are applied immediately to ensure you always have the latest fixes and features.

▸ WHO IS THIS FOR?

• Contractors and carpenters checking level and plumb on site
• DIY enthusiasts hanging shelves, aligning tiles, or leveling appliances
• Engineers and surveyors who need a quick angle reference
• Anyone who has ever balanced a table leg with a folded napkin and wished for a better way

Three tools. One app. No fluff.