Sizing Guide • Updated 2026
What size sump pump do you need?
Three inputs. Thirty seconds. Know exactly which horsepower rating fits your basement — then see every model that qualifies, sorted by flow rate.
HP at a glance
The four residential horsepower tiers
| HP Rating | Basement Size | Conditions | Typical GPH@10ft |
|---|---|---|---|
| ⅓ HP | Under 1,000 sq ft | Low to moderate water table, infrequent cycling | 1,400 – 2,600 |
| ½ HP | 1,000 – 1,500 sq ft | Moderate water table, standard Midwest/Northeast | 2,400 – 4,000 |
| ¾ HP | 1,500 – 2,500 sq ft | High water table, clay soils, frequent cycling | 4,000 – 5,500 |
| 1 HP | Over 2,500 sq ft | Very high water table, full perimeter drain | 5,000 – 7,000+ |
Sizing calculator
Find the right pump for your basement
Answer three questions about your basement. We'll calculate your recommended HP and show every model that qualifies — sorted by flow rate, with no brand preference.
Reference
How to read your existing pump's label
HP or Watts
Look for "HP" or "H.P." on the motor label. If you see watts, divide by 746 to convert: 373W = ½ HP. Fractional ratings like 0.33, 0.5, 0.75 are standard.
Model Number
The model number lets you pull the original spec sheet. Search "[Brand] [Model] spec sheet" to find the manufacturer's performance curve and compare it to your requirements.
Manufacture Date
Usually stamped as a date code or serial number. Pumps over 7 years old near failure are better replaced than repaired — even if they're still technically running.
Voltage
Most residential sump pumps are 120V. Some ¾ HP and 1 HP models require a dedicated 20-amp circuit. Verify before purchasing — your electrician can confirm what's available at the pit.
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