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Calcimator

Bilge Pump Sizing Calculator

Calculate required bilge pump capacity from hull volume, flooding risk, and ABYC guidelines.

Inputs

ft
ft
ft
in
ft

Results

Recommended Pump (GPH)

48,474 GPH

Minimum Required48,474 GPH
Emergency Pump96,948 GPH
Hull Volume4,039 gal
Max Flooding Rate6,788 GPH
Target Pump Time5 min
How to Use This Calculator
  1. Enter the hull length, beam, and bilge depth in feet to estimate internal volume.
  2. Input the number of through-hull fittings, their diameter in inches, and head pressure height.
  3. Review the recommended pump size in GPH and the minimum required GPH per ABYC standards.
  4. Compare recommended and emergency pump sizes to select appropriate bilge pump equipment.
  5. Use the total flooding rate to verify your pump can manage worst-case water ingress.

How the result changes with Hull Beam

Hull BeamRecommended Pump (GPH)
8.742,172 GPH
23111,490 GPH
40193,895 GPH
54261,758 GPH

What each input means

Hull Length
Overall hull length.
Hull Beam
Maximum beam width.
Bilge Depth
Depth from waterline to bilge sump.
Through-Hull Fittings
Number of below-waterline through-hull fittings.
Through-Hull Diameter
Average through-hull fitting diameter.
Head Pressure
Distance from fitting to waterline (water pressure head).

How this is calculated

Worked example, using the default values

  1. Identify Input Parameters
    4 parameters
    Hull Length = 30, Hull Beam = 10, Bilge Depth = 3, Through-Hull Fittings = 4 = 6 input(s) provided
  2. Calculate Recommended Pump
    Recommended Pump
    48474 = 48474
  3. Calculate Minimum Required
    Minimum Required
    48474 = 48474
  4. Calculate Emergency Pump
    Emergency Pump
    96948 = 96948

Engine last updated . Checked against 3 independently-derived tests — how we verify calculators.

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