Pool Water Fill Calculator
Calculate how long it takes to fill your pool and the estimated water cost.
How It Works
This calculator estimates pool fill time based on the flow rate of your water source:
- Garden Hose: A standard 5/8" garden hose delivers approximately 9 gallons per minute (GPM) at typical residential water pressure.
- Two Hoses: Running two garden hoses simultaneously doubles the flow to about 18 GPM.
- Fire Hydrant: With a permit, fire hydrant fills deliver around 1,000 GPM — filling a pool in minutes rather than days.
- Water Truck: Delivery trucks carry about 4,000 gallons per load. The calculator shows how many loads you need.
Water weight is calculated at 8.34 lbs per gallon. Water cost uses your local rate per 1,000 gallons.
Frequently Asked Questions
How long does it take to fill a pool with a garden hose?
A typical garden hose delivers about 9 gallons per minute (540 gallons per hour). For a 20,000-gallon pool, that works out to roughly 37 hours of continuous filling, or about 1.5 days. Using two hoses cuts the time in half.
How much does it cost to fill a pool with water?
Water costs vary by location, but the national average is about $5 per 1,000 gallons. Filling a 20,000-gallon pool would cost roughly $100 in water. Some municipalities offer a one-time sewer credit for pool fills since the water doesn't enter the sewer system.
Can I fill my pool with a water delivery truck?
Yes. Water delivery trucks typically carry 4,000-6,000 gallons per load and cost $200-$600 per load depending on your location. While more expensive than using a hose, trucks can fill a pool much faster and are useful in areas with water restrictions.
Should I fill my pool all at once or in stages?
For new pools, it is best to fill continuously to avoid a visible water line ring. For vinyl liner pools, continuous filling prevents the liner from shifting. However, if you are on a well, you may need to fill in stages to avoid running the well dry — typically filling for a few hours, then pausing for a few hours.