The website vanlifemag.de has published a free calculator that uses two slope angles, wheelbase and track width to work out the required lift height for each wheel of a motorhome. The tool selects the matching step on the levelling ramps and warns if their height is insufficient. Slope data can be entered manually or read from smartphone sensors. The calculation assumes a flat, evenly inclined surface and does not account for dips, kerbs or suspension compression. For Dometicⓘ absorption fridges the manual specifies a maximum tilt of 3 degrees.
