Robot mower manufacturers use both percentage grade and degrees, which makes specifications easy to misread. A 45% slope is not 45 degrees.
Slope rating is only the first filter
Percent grade equals vertical rise divided by horizontal run multiplied by 100. Degrees describe the angle itself, so the numeric values diverge increasingly as slopes get steeper.
Traction and transitions decide real-world performance
Confusing the units can lead to buying a mower for terrain far beyond its design envelope. Marketing pages sometimes emphasize whichever number looks larger, so always identify the unit.
Measure the difficult section, not the average lawn
Measure your slope in one unit and convert before comparing products. Keep a margin below the published maximum, especially where the mower turns, crosses a boundary, or operates on wet grass.
How we research robot mowers
We normalize manufacturer specifications around the buying constraints that actually change the decision: recommended mowing area, navigation architecture, slope capability, cutting-height range, obstacle sensing, charging behavior, multi-zone support, warranty, parts availability, and current pricing. We give more weight to property fit than to feature count.
Prices, specifications, firmware, and configuration-driven features can change. Check the current manufacturer page and local requirements before buying or installing equipment.