Yuzool

Inclinometer

Measure a slope in degrees: lay the phone on it, or stand it on its edge.

Surface
Lay it flat or stand it on an edgeFlat on a shelf or table, you get the bubble with two axes. Stand the phone on its edge against a frame or shelf for the tube level.

About the inclinometer

An inclinometer (a tilt meter or clinometer) measures the angle of a slope against level. Lay your phone on a ramp, board or roof light and it shows the slope in degrees, to a tenth of a degree. Stand it on an edge to measure the slope along that edge only.

Slopes are often given as a percent grade or a ratio instead of degrees. The table below converts the common ones.

Computers have no tilt sensor, so on a laptop or desktop the level shows "No tilt sensor here". Open this page on your phone for the level. The ruler and protractor work on a computer right now.

How to use it

  1. Open this page on your phone (iPhone: tap Allow for motion access).
  2. Lay the phone along the slope, its long side pointing downhill, or stand it on its long edge on the surface.
  3. Read the angle. Tap Lock to freeze the reading if the screen is hard to see where the phone is.
  4. Calibrate once on a steady surface for the most accurate numbers.

Good for

  • Checking a wheelchair ramp, path or drive
  • Measuring the pitch of a shed roof or a skylight
  • Setting the angle of a solar panel, drawing board or bed raise
  • Checking the fall on a patio or gutter

Degrees, percent grade and rise

AngleGradeRise per metre
0.5°0.9%8.7 mm
1°1.7%17.5 mm
2°3.5%34.9 mm
4.8° (1 in 12)8.3%83.3 mm
5°8.7%87.5 mm
10°17.6%176.3 mm
15°26.8%267.9 mm
30°57.7%577.4 mm
45°100.0%1000.0 mm

Grade is the rise divided by the run, times 100: a 45° slope is a 100% grade. A ramp of 1 in 12 (a common maximum for wheelchair ramps) is about 4.8°, or 8.3%.

Questions

How do I convert degrees to percent slope?

Percent grade is the tangent of the angle times 100. For example 1° is about 1.7%, 5° is about 8.7% and 45° is 100%.

How accurate is a phone inclinometer?

It shows a tenth of a degree. After calibration a phone is typically within a few tenths of a degree, which suits DIY slopes. Use a surveyor's instrument for work that must meet a standard.

Can it measure the angle of a roof?

Only where you can safely lay the phone on the surface, such as a shed roof, a skylight or a rafter from inside. Never climb onto a roof to take a reading.

More tools in Bubble Level

Bubble levelSpirit levelLevel appInclinometerAngle finderOnline rulerRuler on screencm rulerInch rulerProtractorCompassDecibel meterSound level meterNoise meter

Everything is in one free app: Bubble Level. Guide: How to hang a picture straight.