Pool & Tank Fill Time
One cubic metre is 1,000 litres and weighs a tonne. Divide by the flow per minute, then by sixty, for hours. The weight matters for floor loading too.
Your numbers
Litres
38,400L
Time to fill
32h
Weight
38.4t
Formula
Time to fill = Length × Width × Depth × 1000 ÷ Flow (L/min) ÷ 60
A domestic tap delivers roughly 15–25 litres a minute, less if other outlets are running.
What to enter
| Input | Default | Accepted range |
|---|---|---|
| Length (m)The measurement across, side to side. | 8 | 0 and up |
| Width (m)The measurement front to back. | 4 | 0 and up |
| Depth (m)How deep it goes. | 1.2 | 0 and up |
| Flow (L/min)How many litres the tap delivers each minute. | 20 | 0.1 and up |
Step by step
Quick reference table
Results when only Length (m) changes and everything else stays put.
| Length (m) | Litres (L) | Time to fill (h) | Weight (t) |
|---|---|---|---|
| 4 | 19,200 | 16 | 19.2 |
| 6 | 28,800 | 24 | 28.8 |
| 8 | 38,400 | 32 | 38.4 |
| 12 | 57,600 | 48 | 57.6 |
| 16 | 76,800 | 64 | 76.8 |
What each result means
| Result | At default values |
|---|---|
| Litres (L)Capacity in litres; one litre is 1,000 cm³. | 38,400 |
| Time to fill (h)How long filling takes at that flow rate. | 32 |
| Weight (t)Weight in tonnes; one tonne is 1,000 kg. | 38.4 |
Common mistakes
A domestic tap delivers roughly 15–25 litres a minute, less if other outlets are running.
Glossary
- Length
- The measurement across, side to side.
- Width
- The measurement front to back.
- Depth
- How deep it goes.
- Flow (L/min)
- How many litres the tap delivers each minute.
- Litres
- Capacity in litres; one litre is 1,000 cm³.
- Time to fill
- How long filling takes at that flow rate.
- Weight
- Weight in tonnes; one tonne is 1,000 kg.
Frequently asked questions
Q. How is Pool & Tank Fill Time calculated?
Time to fill = Length × Width × Depth × 1000 ÷ Flow (L/min) ÷ 60 — One cubic metre is 1,000 litres and weighs a tonne. Divide by the flow per minute, then by sixty, for hours. The weight matters for floor loading too.
Q. Can you walk through an example?
With Length 8m, Width 4m, Depth 1.2m, Flow (L/min) 20, the answer is Litres 38,400L.
Q. What do I need to enter?
Enter Length, Width, Depth, Flow (L/min). The result recalculates as you type, and an empty box counts as zero.
Q. How much does the answer move if I change a number?
Changing only Length (m) moves the answer to Length (m) 4 → Litres (L) 19,200 and Length (m) 16 → Litres (L) 76,800. The table below lays out five steps.
Q. How are the numbers rounded?
Money is shown to the nearest whole unit, percentages to one decimal place and everything else to two. What you see is rounded; the calculation itself carries the unrounded value forward.
Q. Anything to watch out for?
A domestic tap delivers roughly 15–25 litres a minute, less if other outlets are running.
Related calculators
Keep your length units consistent across inputs — mixing centimetres and metres throws results far off.