How Long to Fill a Pool Calculator

Calculate Pool Filling Time

Use this calculator to estimate how long it will take to fill your swimming pool based on the water flow rate and pool dimensions.

Rectangular Pool Dimensions

ft
ft
ft

Circular Pool Dimensions

ft
ft

Oval Pool Dimensions

ft
ft
ft

Known Pool Volume

gallons

Water Flow Rate

GPM
Typical garden hose: 9-17 GPM (34-64 LPM)
%
Pools are typically filled to 90-95% capacity

Typical Flow Rates

Average water flow rates for different sources:

  • Garden hose (5/8"): 9-17 GPM (34-64 LPM)
  • Garden hose (3/4"): 17-21 GPM (64-79 LPM)
  • Fire hydrant: 500-1000 GPM (1893-3785 LPM)
  • Water truck: 250-500 GPM (946-1893 LPM)

Note: Flow rates can vary based on water pressure, hose length, and other factors.

Pool Filling Tips

  • Fill the pool halfway, then add chemicals before completing the fill
  • Monitor the pool during filling to prevent overflow
  • Consider water costs and local water restrictions
  • Use a hose filter to reduce impurities
  • Fill during off-peak hours to maintain water pressure

About Pool Filling Time Calculations

Understanding how long it will take to fill your swimming pool is important for planning and water management. Here are some key factors that affect pool filling time:

Water Pressure and Flow Rate

The flow rate of your water source is the primary factor determining how quickly your pool will fill. Flow rate is typically measured in gallons per minute (GPM) or liters per minute (LPM). Higher water pressure results in higher flow rates and faster filling times.

Pool Volume Calculation

The volume of your pool depends on its shape and dimensions:

  • Rectangular pools: Volume = Length × Width × Average Depth
  • Circular pools: Volume = π × (Diameter/2)² × Depth
  • Oval pools: Volume = π × (Length/2) × (Width/2) × Depth

For pools with varying depths, use the average depth for your calculations.

Water Conservation Considerations

When filling a pool, consider these water conservation tips:

  • Check for and repair any leaks in your pool before filling
  • Use a pool cover to reduce evaporation
  • Consider rainwater harvesting systems for pool top-offs
  • Be aware of local water restrictions during drought conditions

Cost Considerations

The cost to fill a pool depends on your local water rates and the volume of your pool. Most residential water is billed per thousand gallons or cubic meters. For a typical 15,000-gallon pool, the water cost alone can range from $45 to $150 depending on your location.