Every dual action polisher 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. Polishers are grouped as corded long-throw (an orbit of 15 mm or more), corded short-throw (an orbit under 15 mm) and cordless, and use the same scale in every group.
| Factor | Measures | Weight |
|---|---|---|
| Correction | orbit (throw) diameter: a bigger orbit removes defects faster | 30% |
| Value | price | 25% |
| Warranty | warranty length | 15% |
| Power | corded motor rating | 10% |
| Weight | weight, lighter is better | 10% |
| Features | constant speed, soft start, brushless motor, cord reach and lock-on trigger | 10% |
Where the numbers come from
Orbit, speed range, motor rating, backing plate, weight, cord length, features and warranty come from the maker’s spec page or manual, or the maker’s own copy on a retail listing. Some makers label the orbit rate in RPM; it is shown as the maker publishes it. A figure that can’t belong to the product (such as an orbit larger than the backing plate could allow) is 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
Correction is the orbit (throw) diameter, the biggest single difference in how fast a polisher removes defects: 5 mm scores zero and 21 mm full marks.
Value is the current price, on a log scale, so halving the price always counts the same. $600 scores zero and $100 full marks.
Warranty is the maker’s warranty: 1 year scores zero and 5 years full marks. A lifetime guarantee against defects scores full marks. A warranty that requires registering the tool counts at its registered length.
Power is the corded motor rating: 400 W scores zero and 1,100 W full marks. Where a maker gives amps but not watts, the amps are multiplied by 120 V and the factor is marked estimated. Cordless makers publish no comparable motor rating, so every cordless polisher gets the neutral middle score here.
Weight is the weight the maker publishes, lighter being better: 8 lb scores zero and 4 lb full marks. Weights are scored as published, with or without a battery as the maker states, and the product page says which.
Features is 30% for constant-speed electronics that hold the pad speed under pressure, 20% for a soft start that keeps polish from slinging, 20% for a brushless motor, 15% for cordless use or a cord of 20 ft or more (long enough to reach around a car), and 15% for a lock-on trigger.
What isn’t scored
Speed range, backing plate size, forced rotation, whether the cord detaches, whether pads, polish or batteries are included, and release date are listed but not scored.
Missing data
If a minor figure (motor rating or weight) isn’t published, that factor gets the neutral middle score (50) and the product page marks it as estimated. A feature the maker doesn’t mention counts as absent. Two factors are exceptions. A polisher whose maker doesn’t publish its orbit gets zero for correction, the same as the smallest orbit, so a missing figure never lifts a polisher above ones whose makers publish theirs; it is marked estimated and grouped with the short-throw polishers. A maker that doesn’t publish a warranty gets no warranty counted, so that factor scores zero and is 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.