01
The purpose
What does this calculator estimate?
Flow, head, and pump horsepower for bubbling rocks, sheer descents, scuppers, and laminar jets.
Water Features · I4
Fountain & Water Feature Pump Sizing Calculator
Flow, head, and pump horsepower for bubbling rocks, sheer descents, scuppers, and laminar jets.
Measure the inputsMatch the pump to the feature type — each has very different flow needs.
Read the full resultSheer descents are flow-hungry; bubbling rocks need very little.
Check the boundaryAdd about 5 feet of friction allowance to the feature height for head.
Useful forWater FeaturesPlanningComparisonVerification
Live calculation
Feature pump inputs
✓ Checked May 2026
Enter feature type, size, and head.
Calculated result
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Enter the required values to calculate.
Enter the known values. Let the engine handle the calculation.
✓ Formula checked↻ Live result○ No account needed
Planning estimate only. Confirm product labels, equipment specifications, qualified-professional advice and local requirements before acting.
The result, explained
Use the Fountain & Water Feature Pump Sizing Calculator result with context.
Flow, head, and pump horsepower for bubbling rocks, sheer descents, scuppers, and laminar jets.
02
The tool
What information does it use?
- Feature type: Bubbling rock, sheer descent, scupper, laminar, or spray.
- Feature width: For sheer descent / scupper.
- Nozzle count: For laminar / spray jets.
- Head height: Vertical rise to the feature.
03
The method
How to use this calculator
- Feature typeBubbling rock, sheer descent, scupper, laminar, or spray.
- Feature widthFor sheer descent / scupper.
- Nozzle countFor laminar / spray jets.
- Head heightVertical rise to the feature.
04
The relationship
The formula in plain English
Required GPM by type; min HP ≈ (GPM × head) ÷ 3960 ÷ 0.75
Sheer descent 60 GPM/ft · scupper 30–50 GPM each · laminar 4–6 GPM/nozzle · add 5 ft friction.05
Worked through
A worked example: 3 ft sheer descent, 4 ft head
- Sheer descent = 3 × 60 = 180 GPM
- Head = 4 + 5 friction = 9 ft
- Min HP ≈ (180 × 9) ÷ 3960 ÷ 0.75 ≈ 0.55 HP
| Feature | Flow requirement | Example | Pump type |
|---|---|---|---|
| Bubbling rock | 3–8 GPM | Single rock | Small submersible |
| Sheer descent | 60 GPM/ft | 3 ft = 180 GPM | External |
| Scupper | 30–50 GPM each | 2 scuppers = 60–100 | External |
| Laminar jet | 4–6 GPM/nozzle | 4 jets = 16–24 | External |
| Spray fountain | 3–15 GPM/nozzle | Varies | Submersible/external |
06
Why it matters
How the result supports the next decision
Match the pump to the feature type — each has very different flow needs.
Sheer descents are flow-hungry; bubbling rocks need very little.
07
Good inputs
Improve the estimate before relying on it
- Match the pump to the feature type — each has very different flow needs.
- Sheer descents are flow-hungry; bubbling rocks need very little.
- Add about 5 feet of friction allowance to the feature height for head.
- Submersible pumps suit basins; external pumps suit plumbed features.
- Fit a strainer screen to protect the feature pump from debris.
08
The boundary
How to interpret the result
Measurements, equipment specifications, site conditions and local requirements can change the practical result.
The engine reports invalid inputs and safety warnings beside the result. Resolve those messages before using the estimate.
09
Before acting
What should override this estimate?
- Measured site conditions and current test results
- Product labels and manufacturer specifications
- Qualified-professional advice and applicable local codes
10
Common questions
Frequently asked questions
How do I size a fountain pump?
First find the required GPM for your feature type — for example, a sheer descent needs about 60 GPM per foot of width, a scupper 30 to 50 GPM each, a laminar jet 4 to 6 GPM per nozzle. Then add the feature height plus about 5 feet of friction for head, and select a pump delivering that GPM at that head.
How much flow does a sheer descent need?
Roughly 60 GPM per foot of width for a full, clean sheet of water. A 3-foot sheer descent therefore needs about 180 GPM, which usually calls for a dedicated feature pump. Lower flow gives a thinner, more broken sheet, so match the GPM to the look you want.
What pump for a bubbling rock?
Bubbling rocks need very little flow — often just 3 to 8 GPM (a few hundred GPH) for a gentle bubbling effect over the stone. A small submersible pump is typically all that's required. Oversizing makes the effect spurt unattractively, so size modestly and adjust with a valve.
Do I need a submersible or external pump?
Submersible pumps sit in a basin and suit self-contained features like bubbling rocks and small fountains. External pumps are plumbed in line and suit larger features like sheer descents and scuppers fed from the pool. The choice follows the feature design and how it's plumbed.
How do I calculate water-feature pump horsepower?
A practical estimate is required GPM times total head, divided by 3,960, divided by pump efficiency (around 0.75). This gives the minimum horsepower. Always then check the actual pump's flow curve at your head to confirm it delivers the GPM the feature needs.
What size pump for a sheer descent?
About 60 GPM per foot of width — a 3-foot descent needs ~180 GPM.
How much flow for a bubbling rock?
Just 3–8 GPM for a gentle effect; a small submersible pump is plenty.
Submersible or external pump for a water feature?
Submersible for basins and small features; external for larger plumbed features.
Primary sources
Use the result with current guidance.
These official references support safe planning context. Product labels, local requirements and qualified-professional advice take priority over a general calculator estimate.