Enter your Target Engine Horsepower, Induction Type, Fuel Type, Base Fuel Pressure, Boost Pressure, and Fuel System Type into the Fuel Pump Calculator to find your Required Flow Rate, along with Flow Rate in GPH, Effective Fuel Pressure, and a Recommended Flow Rate with a built-in 20% safety margin.
Required Flow Rate
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Flow Rate (GPH)
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Effective Fuel Pressure
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Recommended Flow (with 20% margin)
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Your target horsepower should be the maximum power output you expect from your engine, either current or planned modifications. It's better to overestimate slightly to ensure adequate fuel supply.
Return systems circulate excess fuel back to the tank, maintaining consistent pressure. Returnless systems use a pressure regulator in the tank, requiring different flow calculations.
In forced induction engines, boost pressure acts against fuel pressure. The fuel system must overcome this additional pressure to maintain proper fuel delivery.
Always use the recommended flow rate with safety margin. This accounts for fuel pump aging, voltage drops, and ensures reliable performance under all conditions.
Different fuels have varying energy content and flow characteristics. E85 and methanol require higher flow rates than gasoline to achieve the same power output.
The effective pressure shown is what your fuel system actually sees. Ensure your fuel pressure regulator and pump can maintain this pressure under load.