Every popcorn machine 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. Machines are grouped by kettle size, up to 6 oz, 8 to 10 oz, and 12 oz and up, and use the same scale in every group.
| Factor | Measures | Weight |
|---|---|---|
| Value | price per ounce of kettle | 30% |
| Kettle size | ounces of kernels per batch | 20% |
| Heating power | rated watts per ounce of kettle | 10% |
| Features | heated deck, cart, kernel tray, separate switches and cabinet light | 20% |
| Listing | NSF sanitation listing, or UL or ETL safety listing | 10% |
| Warranty | warranty length | 10% |
Where the numbers come from
Kettle size, power, features, listing and warranty come from the maker’s product page or spec sheet, or the maker’s own copy on a retail listing. Figures that conflict within the maker’s own copy (for example two different weights) are left out rather than guessed. Prices are checked at Amazon and the maker’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 kettle size, in dollars per ounce of kettle, on a log scale, so halving the price always counts the same. $80 per ounce scores zero and $15 per ounce full marks.
Kettle size is the ounces of kernels the kettle takes per batch, on a log scale: 2.5 oz scores zero and 16 oz full marks.
Heating power is the rated watts divided by the kettle size: 75 W per ounce scores zero and 150 W per ounce full marks. More heat per ounce of kernels pops a batch faster and recovers faster between batches.
Features is 30% for a heated deck, 25% for an included cart, 20% for an unpopped kernel tray or old maids drawer, 15% for three or more separate switches (kettle heat, stirrer and light or warmer each on its own) and 10% for a cabinet light.
Listing is full marks for an NSF listing stated by the maker (or testing to NSF/ANSI 4), half marks for a UL or ETL safety listing without NSF, and zero when the maker states neither.
Warranty is the maker’s warranty: no warranty scores zero and 3 years full marks.
What isn’t scored
Popped cups per batch and servings per hour are listed but not scored, since makers measure them in different ways. Kettle material, weight and release date are listed but not scored.
Missing data
If the kettle size, price or wattage isn’t published, that factor gets the neutral middle score (50) and the product page marks it as estimated. Features score neutral only when none of them is published; a feature the maker doesn’t mention otherwise counts as absent. Listing and warranty are the exceptions: a maker that states no listing gets none counted, and a maker that doesn’t publish a warranty gets no warranty counted, so those factors score zero and are marked estimated.
Ties and discontinued models
Products are ranked by score within each group. Discontinued models stay listed but rank below every current model and can be hidden with the “Hide discontinued” filter.