To calculate a percent slope simply you apply the following formula:
If I cover one meter and I rise 30 cm the percentage of slope is 30%.
In practice how to do? Just take a one meter shaft, a spirit level and a plumb line. Put the rule horizontally checking with the level, and then write down how long is the plumb wire, this distance will be the searched percentage.
Make attention don't confuse percentage and degrees. A 100% slope is a 45° slope... (try with the just explained method!)
WARNING: Gradeability for vehicles is measured in percentage, and it differs from the slope in degrees, for example, a 100% slope is a 45 degrees slope. The slope in percent and the slope in degrees are DIFFERENT.
Table of correspondence between percentages slope and degrees slope.
Is maximum slope the only important parameter? No, we must also consider how long it's such an uphill climb to overcome a 10-15 meter such as a ramp to the garage or in hospitals is very different from facing a climb of a hill.
Vehicles and slopes: very often our customer ask us what is the best vehicle that best fits depending on the terrain and climbs to be tackled, we here a brief summary:
slope - electric vehicles test - ALKE ATX 200E - waste collection vehicles
An electric vehicle is able to deal with departures from standstill uphill smoothly
For sandy soils must have an electric vehicle or 110E ATX ATX210E with trim and off road kit "Alkè sand."
Hilly paths uphill 400mt.
In this case it becomes necessary to have an electric vehicle ATX 110E or ATX 210E with HP25 power kit, and we must analyze the length and terrain characteristics.
Dirt up and down
For the dirt road you must have an electric vehicle ATX 110E or 210E with SUV attitude and you have to go and analyze the slope of the most insidious that should not be above 30% if it is between 30% and 40% becomes need the kit HP25.