Every robotic pool cleaner 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. Cordless and corded robots are ranked separately.
| Factor | Measures | Weight |
|---|---|---|
| Value | current price | 25% |
| Cleaning | floor, walls, waterline, surface | 25% |
| Navigation | how it covers the pool | 15% |
| Warranty | years of cover | 15% |
| Pool size | largest rated pool | 10% |
| Features | app, schedule, pickup, cable, caddy | 10% |
The factors
Value is the current lowest checked price, on a sliding scale: $2,500 or more scores zero and $250 or less full marks, with each halving of the price worth the same. Prices are checked by hand and dated on every page; a robot with no current price gets the neutral middle score.
Cleaning scores what the robot cleans:
| Cleans | Score |
|---|---|
| Floor, walls, waterline and surface | 100 |
| Floor, walls and waterline | 85 |
| Floor and walls | 60 |
| Floor only | 20 |
The waterline is where sunscreen, oil and dirt leave a ring, and it’s the part most often still scrubbed by hand. Surface skimming picks up floating leaves and pollen before they sink. If a maker says a robot climbs walls but not whether it cleans the waterline, it scores as floor and walls and the factor is marked estimated.
Navigation scores how the robot covers the pool. Makers name their systems differently; each is grouped by what it actually uses:
| Navigation | Score |
|---|---|
| Camera + ultrasonic | 100 |
| Camera | 85 |
| Ultrasonic + 3D light | 85 |
| Ultrasonic | 75 |
| Gyroscope mapping | 65 |
| Gyroscope or sensors | 50 |
| Fixed pattern | 35 |
| Random | 10 |
Ultrasonic sensors and cameras let a robot see walls, steps and obstacles before it reaches them and plan rows across the floor. A gyroscope keeps it driving straight and turning on a pattern but finds walls by bumping into them. Random robots bounce off walls and change direction, which leaves spots uncleaned in odd-shaped pools.
Warranty is the length of the standard warranty: 1 year scores zero and 3 years full marks. Pool robots work underwater every week, and motors and seals are the usual failures, so the warranty matters more than for most products.
Pool size is the largest pool the maker rates the robot for: 300 sq ft scores zero and 1,200 sq ft full marks. Most home pools are 15 × 30 to 20 × 40 ft (450 to 800 sq ft), so any robot rated for 1,200 sq ft or more handles nearly all of them, and bigger ratings add nothing. Some makers rate by area and some by pool length; a length is converted at the usual 2:1 shape (a 50 ft pool counts as 50 × 25 ft, 1,250 sq ft) and marked estimated.
Features is the share of these the robot has: app control, scheduling, an easy pickup (a cordless robot that climbs to the waterline, floats up or returns to a dock, so you don’t need a hook), a swivel cable that stops a corded robot’s cable twisting, and an included caddy. A feature the maker doesn’t say either way about is left out of the share, and the factor is marked estimated.
What isn’t scored
Run time, water flow (gallons per hour) and filter fineness are listed on each product page but not scored. Corded robots run a timed cycle rather than until a battery is flat. Makers measure water flow differently. And filter ratings range from 3 to 180 microns depending on how the maker measures them, so the numbers can’t be compared across brands. Independent tests are listed where they exist, but each reviewer tests in their own pool with different debris, so they aren’t scored yet.
Missing data
If a figure isn’t published, that factor gets the neutral middle score (50) and the product page marks it as estimated.
Ties and discontinued models
Products are ranked by score within cordless or corded. Discontinued models stay listed but rank below every current model and can be hidden with the “Hide discontinued” filter.