Booster Pump Calculator
Calculate the booster pump size needed to increase water pressure for multi-story buildings or low-pressure supply lines.
Results
Visualization
How It Works
Booster pumps increase water pressure when the incoming supply is too low. Each story of elevation costs about 4.33 PSI. The pump must overcome both the deficit and elevation loss.
The Formula
Boost PSI = Desired - Incoming + Elevation Loss
Elevation Loss = (Stories - 1) x 10 ft x 0.433 PSI/ft
HP = (GPM x Head ft) / (3960 x Efficiency)
Elevation Loss = (Stories - 1) x 10 ft x 0.433 PSI/ft
HP = (GPM x Head ft) / (3960 x Efficiency)
Variables
- 0.433 — PSI per foot of elevation (water column)
- 2.31 — Feet of head per PSI
Worked Example
25 PSI incoming, want 55 PSI, 2-story: Elevation loss = 4.33 PSI. Boost = 55 - 25 + 4.33 = 34.3 PSI. Head = 79 ft. HP = (12 x 79) / (3960 x 0.6) = 0.40 HP. Use 0.5 HP.
Practical Tips
- Install a pressure gauge to verify actual incoming pressure
- Check if a clogged PRV is causing low pressure before buying a booster
- Include an expansion tank on the outlet side
- Variable speed boosters adjust to demand and save energy