Bilge Pump Sizing Calculator

Calculate pump capacity for your vessel

Vertical distance from bilge to discharge

Pump Recommendations

Primary Pump --
Backup Pump --
Base Requirement --
Head Loss Factor --
Risk Factor --
Emergency Capacity --

Common Pump Sizes

Boat Size Primary GPH Backup GPH
Under 20 ft500-800500
20-30 ft1000-1500500-800
30-40 ft1500-20001000
40-50 ft2000-30001500
50+ ft3000+2000+

Bilge Pump Best Practices

Installation:

  • Mount at lowest point of bilge
  • Use strainer to prevent clogging
  • Wire directly to battery (not through switch panel)
  • Install check valve to prevent backflow

Redundancy:

  • Multiple pumps in different locations
  • Manual backup pump (always carry)
  • High-water alarm recommended
  • Test pumps before every trip