Water Tank Fill Time Calculator
Time to fill a tank from its current level at a given flow rate.
Results
Minutes
66.7
min
Hours
1.111
h
Volume
800.0
L
Flow rate
0.720
m³/h
What this tool does
To measure a flow rate without a meter, time how long a bucket of known size takes to fill: ten litres in fifty seconds is twelve litres a minute. Real flow drops as the tank fills if it is fed from a height, so treat the answer as a lower bound on the time.
Formula
time = volume ÷ flow rate
Variables
| Symbol | Meaning | Unit |
|---|---|---|
v | Tank volume | L |
q | Flow rate | L/min |
cu | Current level | % |
T | Minutes | min |
TH | Hours | h |
VL | Volume | L |
QH | Flow rate | m³/h |
Worked example
- Tank volume1000 L
- Flow rate12 L/min
- Current level20 %
- Minutes66.7 min
- Hours1.111 h
- Volume800.0 L
- Flow rate0.720 m³/h
Limitations
- The result is an estimate based only on the values you type. Real situations often include factors this calculator does not know about.
- The formula assumes ideal conditions: no friction losses, no air resistance and no efficiency losses unless you enter them.