Water tank fill time calculator
Handy for timing a pump run or a water truck delivery.
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How to use it
- Enter tank capacity, flow rate, current level and target level.
- The result appears straight away and updates as you edit.
- Copy the result, or copy a link that keeps the same values to share it.
How it is calculated
Liters needed = capacity × (target % minus current %) ÷ 100. Time (min) = liters ÷ flow (L/min).
Example
Inputs: Tank capacity = 2,000 L, Flow rate = 20 L/min, Current level = 0 %, Target level = 100 %. Result: Fill time: 100 min; In hours: 1.67 h; Water to add: 2,000 L.
Limits and caveats
- It assumes a steady flow; real flow changes with supply pressure and tank height.
- To measure flow, time how many seconds it takes to fill a bucket of known size.
Questions about this tool
How long does a 2,000 L tank take to fill?
At 20 liters per minute it takes 100 minutes, or 1 hour 40 minutes.
How do I find my pump flow?
Read it from the pump plate, or fill a 10 L bucket and divide 10 by the minutes it took.
My pump is rated in m³/h. What do I enter?
One m³/h equals 1,000 ÷ 60, about 16.67 liters per minute.