This overall score is made up of performance (60%) and ease of use (40%). Scores are comparable across types (it's unfair to expect a cheap blender to be as powerful as a high-performance, professional blender).
We check how stable the jug is on the unit as well as how heavy it is to lift, how easy the controls are to use and how easy the blender is to clean. The ease of use score accounts for 40% of the overall score.
Overall performance is based on how each type of blender performs its core tasks. All are tested for blending a soft food, crushing ice and blending kale. Extra tests include: chopping carrots for standard blenders and green smoothie for personal blenders. High-performance blenders are tested on both of these, plus nut butter and sorbet.
Standard blenders are cheaper; core functions are to blend soups and smoothies and crush ice. High-performance blenders are more powerful and can cost over $1000; suitable for nut butters, sorbets and making hot soups from raw ingredients using friction. Personal blenders are ideal for single-serve smoothies and can come with chopping attachments. Scores are only comparable by type.