Loodis

Slope in percent, mm per metre and 1:x

Degrees are what a sensor measures, but builders think in other units. A drain needs 1–2 %, a pipe 1:50, a roof 4/12. Loodis shows all of them – and simply how many millimetres to raise one end.

Get it on Google PlayNo ads · No account
Held reading in Loodis with the time: 1.2° in degrees, percent grade, rise per foot and roof pitch

Units of slope

  • Degrees (°) – the angle from horizontal. 0° is level, 90° is vertical.
  • Percent (%) – how much it rises per 100 units of length. 2 % = 2 cm per metre.
  • mm per metre (mm/m) – millimetres of rise per metre. 1 % = 10 mm/m.
  • Ratio 1 : x – one unit of rise for every x units of length. 1 : 50 = 2 %.
  • Roof pitch x/12 – inches of rise per 12 inches of run, used in the US.
  • Inches per foot (in/ft) – the same as x/12 for small slopes.

Formulas

With θ the angle in degrees:

  • Percent = tan(θ) × 100
  • mm per metre = tan(θ) × 1000
  • Ratio x = 1 ÷ tan(θ)
  • Roof pitch = tan(θ) × 12
  • Rise = tan(θ) × length

For small angles 1° ≈ 1.75 % ≈ 17.5 mm/m ≈ 1 : 57. Use the slope calculator to convert any value.

How much to raise one end

Stand the phone on its edge on a shelf, worktop or pipe. Loodis shows the tilt and how many millimetres to raise the low end per metre. With Pro you set the real length of the object – 80 cm shelf, 1.8 m worktop – and Loodis says: Raise the right end by 6 mm.

That's the number you need when you put shims under a leg or adjust a bracket, without any arithmetic.

Loodis Edge mode: tube level with the phone on its long edge, showing how much to raise one end

Typical slopes

  • Shower floor towards the drain: about 1–2 %.
  • Balcony or patio away from the house: about 1–2 %.
  • Gutter: about 3–5 mm per metre.
  • Drain pipes: commonly 1 : 40 to 1 : 100, depending on the diameter.

These are rules of thumb; always check the building rules where you live.

Units in Loodis

Degrees are free. Percent, mm per metre, 1:x, roof pitch and the millimetre guidance are part of Loodis Pro – tap the unit button to try them three times for free. In the held reading all four units are shown at once.

Read next

Slope calculator

Convert degrees, percent, mm/m, 1:x and roof pitch. Tables included.→

How to level a shelf with your phone

Hang a shelf level and see how many millimetres to raise one end.→

Loodis Pro

Loodis Pro adds the camera level, slope in % and mm/m, millimetre guidance, zero, full-screen green and sound guide. One-time purchase, 3 free tries.→

Measure it with Loodis

Bubble level for Android. Calibrate on any table, read the tilt in degrees and try every Pro feature three times for free.

Get it on Google Play