Every sump pump gets a score from 0 to 100% built from four 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. Pumps are grouped by motor size, up to 1/3 HP and 1/2 HP and up, and flow has its own scale for each group.
| Factor | Measures | Weight |
|---|---|---|
| Value | price per 1,000 gallons an hour at 10 ft | 30% |
| Flow | gallons an hour at 10 ft of lift | 30% |
| Build | cast iron housing, a switch that fits a narrow pit, alarm or Wi-Fi | 20% |
| Warranty | warranty length | 20% |
Where the numbers come from
Flow, switch type, housing material and warranty come from the maker’s product page, performance table, spec sheet or manual, or the maker’s own copy on its Amazon listing. When a maker gives only a curve, the 10 ft figure is read from it and the product page says so. Prices are checked at Amazon and the maker’s own store, and the lowest is used.
The factors
Value is the current price divided by the flow at 10 ft of total head, in thousands of gallons an hour, on a log scale, so going from $80 to $40 counts as much as going from $120 to $60. $130 per 1,000 GPH scores zero and $40 full marks.
Flow is gallons an hour at 10 ft of total head: for pumps up to 1/3 HP, 1,500 GPH scores zero and 3,000 GPH full marks; for 1/2 HP and up, 2,500 GPH scores zero and 5,000 GPH full marks.
Build counts three things that make a pump last and protect the basement: a cast iron motor housing, a vertical float, electronic or diaphragm switch that fits a narrow pit (a tethered float needs a wide one and can snag), and a high water alarm or Wi-Fi monitor in the box. Each is a third of the factor.
Warranty is the length of the warranty: 1 year scores zero and 5 years full marks.
What isn’t scored
Horsepower, flow at 0 ft, maximum lift, discharge size, current draw and cord length are listed but not scored. Horsepower only sets the group; the flow at a real lift is what’s scored.
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 each group. Discontinued models stay listed but rank below every current model and can be hidden with the “Hide discontinued” filter.