Calculate waterfall flow rate, pump size, gallons per hour, gallons per minute, flow per inch of waterfall width, pond turnover, head height adjustment, and water volume over time. Use this waterfall flow calculator for pond waterfalls, garden streams, fountains, cascades, pondless waterfalls, spillways, and backyard water features.
Flow from waterfall width:
The calculator multiplies waterfall width by the selected flow style to estimate gallons per hour.
Pump flow after head height:
Enter pump rated flow, head height, and pipe loss to estimate real flow at the waterfall.
Pond turnover:
Enter pond volume and desired turnovers per hour to estimate the flow needed for circulation.
Volume and time:
Enter a known volume and fill time to calculate measured waterfall or pump flow.
A waterfall flow calculator helps estimate pump size, waterfall appearance, pond turnover, stream volume, and flow rate before choosing equipment.
It can be useful for pond waterfalls, garden waterfalls, pondless waterfalls, streams, cascades, spillways, fountains, koi ponds, and backyard water features.
Your result shows estimated waterfall flow in gallons per hour, gallons per minute, cubic feet per second, liters per minute, recommended pump size before head loss, actual flow after head loss, pond turnover time, stream water volume, and daily water movement.
A common estimate is about 100 to 200 gallons per hour per inch of waterfall width. Light flows may use less, while heavy waterfalls may need more.
Estimate the desired waterfall flow, then choose a pump that can deliver that flow at your actual head height after pipe, filter, valve, and fitting losses.
Head height is the vertical lift from the pond water level to the waterfall outlet. Higher head height usually lowers pump flow.
Many pond setups aim for roughly one pond turnover per hour, but the ideal rate depends on fish load, filtration, waterfall size, pond design, and water quality needs.