Every electric grain mill gets a score from 0 to 100% built from six factors, which maps onto the 5-point rating shown on the site (a 0% score would be 1.5 stars; a perfect score, 5). Each factor is scored against fixed reference points, not against the other products in the list, so adding a new model never moves another model’s rating. Mills are grouped by class: countertop flour mills, commercial disc mills, and feed and hammer mills. All three classes use the same scale.
| Factor | Measures | Weight |
|---|---|---|
| Value | price per 100 W of rated motor power | 20% |
| Output | the maker's claimed flour or feed output per hour | 25% |
| Motor | rated motor power | 10% |
| Grind control | stepless knob, number of settings, or number of sieves | 15% |
| Versatility | beans and legumes, oily seeds and wet grinding | 10% |
| Warranty | warranty length | 20% |
Where the numbers come from
Motor power, output, grind adjustment, what each mill can grind and warranty come from the maker’s product page or manual, from the maker’s own copy on a retail listing, or from a specialty retailer’s spec sheet where the maker sells only through retailers. Output is recorded as the maker states it. A weight per hour is used as published, with kilograms converted at 2.2046 lb per kg. Where a maker gives a range, the top of the range is used, and for disc mills the dry wheat or corn figure. A batch claim such as “24 cups in under 10 minutes” is divided out to cups per minute. Prices are checked at Amazon and the maker’s or retailer’s own store, and the lowest price at a store the page links to is used.
The factors
Value is the current price divided by the rated motor power, in dollars per 100 W, on a log scale, so halving the price always counts the same. $60 per 100 W scores zero and $5 per 100 W full marks.
Output is the maker’s claimed output in pounds per hour, on a log scale: 10 lb an hour scores zero and 150 lb an hour full marks. Where a maker gives only cups of flour per minute, cups are converted at 0.265 lb per cup of whole-wheat flour (about 120 g) and the score is marked estimated.
Motor is the rated motor power on a log scale: 300 W scores zero and 3,000 W full marks.
Grind control is how finely the texture can be set. A stepless knob or dial scores full marks. A mill with a stated number of settings or interchangeable sieves scores from zero for one up to full marks for six or more. A mill with one fixed texture scores zero.
Versatility is 40% for grinding beans and legumes, 30% for oily seeds and 30% for wet grinding of soaked beans or rice, as the maker states them. A mill the maker says is for dry grain only scores zero.
Warranty is the maker’s warranty on the mill and motor: 1 year scores zero and 10 years full marks. A lifetime warranty on the whole mill scores full marks.
What isn’t scored
Milling type (impact, stone, disc or hammer), motor speed, hopper and flour canister size, continuous feed, overheat protection, noise, weight and release date are listed but not scored.
Missing data
Output and motor power separate these mills more than anything else, so a mill whose maker publishes no output figure scores zero on output, and one with no published motor power scores zero on both motor and value. Each is marked estimated. Warranty works the same way: a maker that doesn’t publish one gets no warranty counted, so that factor scores zero, the same as a one-year warranty, and is marked estimated. Grind control and versatility are minor factors. If either isn’t published it gets the neutral middle score (50), and the product page marks it as estimated. Versatility scores neutral only when the maker says nothing about beans, oily seeds or wet grinding.
Ties and discontinued models
Products are ranked by score within each class. Discontinued models stay listed but rank below every current model and can be hidden with the “Hide discontinued” filter.