Sump Pump Sizing Calculator

Size sump and sewage pumps based on GPM and head requirements

Basin Information

Water level change per cycle

Water Inflow

Discharge Head

Pump Requirements

Required GPM --
Recommended HP --
Total Dynamic Head --
Static Head --
Friction Head --
Basin Volume/Cycle --
Max Cycles/Hour --
Tip: Select pump rated for at least 150% of calculated GPM at operating head for adequate safety margin.

Typical Pump Capacities

HP @ 5ft Head @ 10ft Head @ 15ft Head
1/430 GPM20 GPM--
1/350 GPM40 GPM25 GPM
1/260 GPM50 GPM40 GPM
3/475 GPM65 GPM55 GPM
190 GPM80 GPM70 GPM
Actual performance varies by manufacturer

Selection Guidelines

Sump Pumps:

  • 1/3 HP: Light duty, small basements
  • 1/2 HP: Most residential applications
  • 3/4+ HP: High water tables, large areas

Sewage Pumps:

  • 1/2 HP: 1-2 fixtures below sewer
  • 3/4-1 HP: Full bathroom below sewer
  • 2" solids handling minimum

Basin Sizing Guide

Basin Diameter Gallons/Inch Typical Use Max HP
14"0.66Utility/laundry1/3
18"1.10Residential sump1/2
24"1.96Sewage/heavy duty1
30"3.06Commercial2
36"4.41Large commercial3+