Pool Fill Time Calculator
Time and cost to fill a pool from volume and hose flow.
What it does
Filling a pool takes longer than hoses suggest. Ten thousand gallons at five gallons per minute needs two thousand minutes, over thirty three hours. Cost follows from the water rate.
The tool above takes pool volume, hose flow, and rate and returns fill time, water cost, and hourly rate. The defaults 10000 gal at 5 GPM match the worked example, so the page opens showing 33h 20m. Switch to metric for liters.
Time divides volume by flow. Cost multiplies volume by rate. Hourly rate multiplies flow by sixty: 5 GPM is 300 gal/h. Metric mirrors through 3.785411784 liters per gallon for the same dollars on equivalent water.
Hose flow varies with pressure, length, and nozzle, so time a bucket to pin GPM. Split fills across days to protect wells and meet restrictions. Sewer charges may ride on metered fills unless separately handled.
This page shows the formulas, one full hand checked example at 10000 gallons, a reference table, and practice checks that run through the tool in both unit systems.
How to use
- Pick Imperial (gal) or Metric (L).
- Type pool volume in the active unit.
- Type hose flow from a bucket test.
- Type water cost per unit.
- Read Fill time as hours and minutes.
- Read Water cost and Hourly rate to plan.
Formula
- volume
- Pool gallons or liters.
- flow
- GPM or L/min at your hose.
- rate
- Dollars per gallon or per liter.
Steady flow assumed. Pressure drops and kinked hoses cut real GPM below label.
Worked example
Example: 10000 gal at 5 GPM
Fill ten thousand gallons with a 5 GPM hose at half a cent per gallon.
- Minutes: 10000 / 5 = 2000 min.
- Hours: 2000 / 60 = 33h 20m.
- Cost: 10000 x 0.005 = $50.00.
- Hourly: 5 x 60 = 300 gal/h.
- Metric mirror 37854.12 L fills in 33h 20m.
- Split across days for wells and rules.
Reference table
| Pool gal | Time | Cost at 0.005 |
|---|---|---|
| 5000 | 16h 40m | $25.00 |
| 10000 | 33h 20m | $50.00 |
| 20000 | 66h 40m | $100.00 |
Limits
- Steady flow only.
- Rate as entered. Sewer and fees sit outside unless in rate.
- No evaporation or splash loss here.
- Estimate, not meter proof.
Common mistakes
- Using label GPM without a bucket test.
- Mixing gallons with liters in one ratio.
- Reading minutes as hours.
- Forgetting cost is volume times rate, not time times rate.
- Planning one shot fills for wells.
Try it yourself
Quick checks. Answers sit tucked under each question.
5000 gal at 5 GPM, 0.005?
Time 16h 40m, cost $25.00, 300 gal/h.
10000 L at 20 L/min, 0.002?
Time 8h 20m, cost $20.00, 1200 L/h.
Questions
10000 gal at 5 GPM?
33h 20m.
Cost?
Volume times rate. Here $50.00.
My GPM?
Time a 5 gal bucket: GPM is 5 over minutes.
Liters?
Same math per liter. Here 33h 20m.
Sewer?
Only if folded into rate here.
Wells?
Split fills to protect supply.