Cistern Fill and Empty Time

Cistern Fill and Empty Time Calculator

The Cistern Fill and Empty Time Calculator determines how long it will take to fill or empty a cistern based on its volume, fill rate, and empty rate. This tool is handy for water management in agriculture, construction, and residential contexts, where understanding water capacity is essential. By entering the cistern's volume, fill rate (US gallons per hour), and empty rate (US gallons per hour), you can calculate the time in hours and days it will take to fill or empty the cistern.

Cistern Fill and Empty Calculator

Cistern Volume (gallons): gal US
Fill Rate
(gallons per hour):
gal/hr
Empty Rate
(gallons per hour):
gal/hr

Results:

Time to Fill: hrs d
Time to Empty: hrs d
hrs d

Calculator

  1. the capacity of the cistern in US gallons
  2. the rate at which water fills the cistern in US gallons per hour
  3. the rate at which water is being emptied from the cistern in US gallons per hour

Results

  1. the estimated number of hours required to fill the cistern if there is no emptying
  2. the estimated hours needed to empty the cistern if there is no filling
  3. net Fill or Empty Time: based on the difference between fill and empty rates, showing the expected time to reach full or empty status

Formulas

Time to Fill (if only filling):
TimetoFill = CisternVolume / FillRate
Time to Empty (if only emptying):
TimetoEmpty = CisternVolume / EmptyRate
The formula for Net Fill Time is:
If the fill rate exceeds the empty rate, the cistern will eventually fill up. 
Net FillTime = cisternVolume / (FillRate - EmptyRate)
The formula for Net Empty Time is:
If the empty rate exceeds the fill rate, the cistern will eventually empty. 
Net Emptytime = cisternVolume / (EmptyRate - FillRate)

Example Calculation:

Cistern Volume of 2000 gallons.
Fill rate of 100 gallons per hour.
Empty rate of 50 gallons per hour.

Time to Fill (no emptying):
5000 ÷ 200 = 25 hours or approximately 1.04 days.

Time to Empty (no filling):
5000 ÷ 100 = 50 hours or approximately 2.08 days.

Net Fill Time (considering both rates):
5000 ÷ (200 - 100) = 5000 ÷ 100 = 50 hours, or approximately 2.08 days.

In this scenario, it will take 50 hours (2.08 days) to fill the cistern considering both the filling and emptying rates.

If you have any questions or comments please Contact Us
Privacy Policy
© 1998, VmNet.