How we rank products

Every ranking on this site is calculated, not hand-picked. Here is the whole method.

1. Specs come from the manufacturer

We enter only figures the manufacturer publishes and link the page we used under every product. If a figure isn't published we show "Not listed" instead of guessing.

2. Each spec is scaled from 0 to 1

Each criterion has a fixed reference range, from a "weakest reasonable" value to a "best in class" value (for example 0.2 to 2.5 acres of rated lawn area for robot mowers). A product's figure is placed on that range and clamped between 0 and 1, so scores stay meaningful as products are added. For specs where lower is better, such as weight, the range runs the other way. Yes/no features count as 1 or 0. The ranges are listed below.

3. Weights decide what matters most

Each category lists its criteria and weights on the page. The score is the weighted average, multiplied by 10:

score = 10 × Σ(weight × scaled value) ÷ Σ(weight)

4. How missing data is scored

If a spec isn't published (for example a rated motor figure when the maker prints only peak watts), the product scores at the lowest value any product in that category actually published, so an unpublished figure never outranks a published one. The page marks each such cell with an asterisk. Yes/no features that aren't stated count as no. Nothing is ever scored at the category average.

5. Prices and ratings switch on automatically

When our retailer feeds supply a current price or customer rating for at least 60% of products in a category, two more criteria join the formula: Price / value (20%) and Customer rating (15%, discounted when there are few reviews). Until then we show "Check price" and never estimate a price.

6. What the score can't tell you

Specs don't capture cut quality, noise in use, reliability, app quality or dealer support. Runtime and lawn area are each maker's own claims, measured in its own way. Where a maker lists only volts and amp-hours, we multiply them to get watt-hours and label the result as computed; height ranges and metric conversions are labelled computed too. A weight the maker says excludes the battery is not ranked. Nothing here is legal advice. Use the score to shortlist, then read the pros, cons and sources. When we add hands-on testing notes, we label them clearly.

7. Money never changes the order

We earn affiliate commissions from some retailers. Commission rates are not an input to the formula, and no brand can pay for placement. See our affiliate disclosure.

Criteria by category

Robot Lawn Mowers

• Max lawn area: 30% · range 0.2 → 2.5 acres
• Max slope: 20% · range 30 → 84 %
• Cutting width: 15% · range 7 → 16 in
• Mowing time per charge: 15% · range 50 → 240 min
• Cutting-height range: 10% · range 1 → 3 in
• Wire-free option: 10% · yes/no

Cordless Lawn Mowers

• Deck width: 25% · range 16 → 30 in
• Kit battery energy: 20% · range 140 → 800 Wh
• Runtime: 15% · range 40 → 90 min
• Rated lawn size: 15% · range 0.25 → 1 acres
• Cutting-height range: 10% · range 1.5 → 3 in
• Self-propelled: 10% · yes/no
• Listed weight: 5% · range 120 → 34 lb

Cordless String Trimmers

• Cutting swath: 25% · range 12 → 17 in
• Runtime: 25% · range 20 → 80 min
• Kit battery energy: 20% · range 48 → 320 Wh
• Listed weight: 20% · range 13 → 4 lb
• Brushless motor: 10% · yes/no

Cordless Leaf Blowers

• Air volume: 35% · range 300 → 880 CFM
• Air speed: 20% · range 90 → 200 mph
• Runtime: 20% · range 18 → 120 min
• Kit battery energy: 15% · range 100 → 480 Wh
• Listed weight: 10% · range 18 → 4 lb