Measurement tool
Spirit Level.
Uses your phone's accelerometer to show tilt on both axes. The bubble turns teal when you're within 1° of perfectly level.
Uses your device gyroscope to show real‑time tilt. Perfect for leveling shelves, pictures, and furniture.
Needs orientation sensor
Roll (γ)
0.0°
left ↔ right
Pitch (β)
0.0°
forward ↕ back
Place device flat and tap "Calibrate" to zero the reading for best accuracy.
Frequently asked questions.
How does a digital spirit level work?
Your phone contains a MEMS (Micro-Electro-Mechanical System) accelerometer — a microscopic sensor etched onto a silicon chip that measures the direction and magnitude of gravitational acceleration. When your phone lies perfectly flat, gravity pulls straight down through the chip and the readings on both axes are zero. Tilt the phone and gravity's pull shifts along the horizontal axes proportionally to the angle of tilt. We take those raw axis readings, apply inverse trigonometry, and convert them into degrees of roll and pitch in real time. The same chip is used by your phone for screen rotation, step counting, and gaming — we're just reading its data directly and displaying it as a level.
How do I get the most accurate reading?
For the best accuracy, place the phone flat on the surface you want to measure rather than holding it in your hand — even a slight grip shifts the reading. Let it settle for 1–2 seconds before reading the angle, as the sensor takes a moment to stabilise after movement. If readings seem consistently off even on a known flat surface (like a granite countertop or a machined metal plate), tap the Calibrate button while the phone is on that surface to zero out any sensor bias. Once calibrated, the offset is remembered for the session. Keep the phone away from vibrating surfaces like appliances in operation — vibration introduces noise that makes the reading fluctuate.
What is roll vs pitch?
These two terms describe the two independent axes of rotation your phone can tilt along. Roll (Tilt X) is the left-right lean — imagine the phone tipping sideways, with its left edge going down while its right edge goes up, as if it were rolling along its long axis. Pitch (Tilt Y) is the forward-back tilt — the phone leaning toward its top or bottom edge, like the nose of an aircraft pitching up or down. A surface can be tilted in both directions at once, and the 2D bubble display shows both simultaneously. The bubble settles at the exact geometric centre when both roll and pitch are within 1° of zero, which is when the display turns teal to confirm level.
Can I use this for hanging pictures?
Yes, absolutely — it's one of the most practical everyday uses. Lay the phone flat on top of the picture frame or directly against the hanging wire, then slide one side up or down until the bubble centres and the display reads '✓ Level'. The 1° tolerance built into the confirmation is intentional: at 1° of tilt, a 60 cm wide picture frame is only 1 cm higher on one side than the other — well below what the human eye detects as a lean in a typical room. You can also use it to check that a shelf bracket is level before tightening the screws, or to verify a TV mount is straight before drilling into the wall.
How a Digital Spirit Level Works
A traditional spirit level uses a small sealed tube filled with liquid and an air bubble. When the surface is perfectly horizontal, the bubble floats to the centre of the tube. Our digital version replaces that tube with your phone's MEMS accelerometer — a tiny chip that measures the direction and magnitude of gravitational acceleration. When your phone is flat, gravity pulls straight down through the chip. Tilt the phone in any direction and gravity shifts, letting the sensor calculate your exact angle to a fraction of a degree.
Roll vs. pitch — understanding the two axes
A phone can tilt in two independent directions at once, and the spirit level measures both simultaneously. Roll (sometimes called Tilt X) is the left-right lean — imagine the phone tipping sideways toward its left or right edge. Pitch (Tilt Y) is the forward-back tilt — the phone leaning toward its top or bottom edge. Each axis is displayed separately in degrees, so you can see not just whether a surface is level but precisely which direction and by how much it is off.
The 2D bubble display combines both readings into a single visual indicator. The bubble sits at the centre of the target circle when both roll and pitch are within 1° of zero — at which point the display turns teal to confirm you are level. This matches the ±1° tolerance of most quality hardware spirit levels.
Tips for the most accurate readings
Place the phone directly on the surface you want to measure — do not hold it in your hand, as your grip will introduce motion noise. On a smooth flat surface (like a countertop or shelf), the reading should stabilise within one or two seconds. If you notice a consistent offset even on a known flat surface, tap the Calibrate button to zero out that offset. This is useful if your phone's accelerometer has a small factory bias, which is common on budget devices.
Avoid surfaces that vibrate — running machinery, a washing machine in spin cycle, or a car engine will cause the reading to fluctuate. For the cleanest result, set the phone down gently, wait for the readout to stabilise, then take your measurement.
Everyday uses for a phone spirit level
Hanging pictures and mirrors is one of the most common uses — lay the phone on the frame and adjust until the bubble centres. Installing shelves is another: place the phone on the shelf while you tighten the brackets. Levelling appliances like washing machines, fridges, and dishwashers reduces vibration and noise; most have adjustable feet and a spirit level tells you exactly how much to turn them. Setting up photography and video equipment — a level camera horizon makes post-processing much easier. Outdoor use includes checking whether a tent platform is reasonably level before setting up camp, or verifying a caravan is balanced before extending the stabiliser legs.
Spirit level vs. inclinometer — which should you use?
A spirit level is designed for one specific task: confirming a surface is perfectly horizontal (0° tilt). An inclinometer measures any angle from flat ground up to a vertical wall. If you need to know "is this shelf level?" use the spirit level. If you need to know "what angle is this ramp?" or "what is the pitch of this roof?", use the inclinometer. Both tools are available here and use the same accelerometer sensor in your phone.