Rectangular Water Tank Capacity Calculator
Litres in a rectangular tank or sump from inside dimensions — and the size you need for a target capacity.
Measure INSIDE faces — 230 mm walls steal ~15% from outside dimensions on a small sump. Keep 100–150 mm freeboard below the overflow when sizing usable capacity.
Formula
Rectangular Water Tank Capacity Calculator is a free rectangular tank capacity for civil engineers, contractors and quantity surveyors — instant, accurate and 100% client-side, with the governing formula and reference shown next to the result so the number can be defended, not just quoted.
About Rectangular Water Tank Capacity Calculator
Litres in a rectangular tank or sump from inside dimensions — and the size you need for a target capacity. The calculation implements V = L × W × depth × 1000 L/m³ (Geometry; IS 3370 water-retaining structures (context)). Measure INSIDE faces — 230 mm walls steal ~15% from outside dimensions on a small sump. Keep 100–150 mm freeboard below the overflow when sizing usable capacity.
How to use Rectangular Water Tank Capacity Calculator
- 1Enter Inside length in m.
- 2Enter Inside width in m.
- 3Enter Water depth in m.
- 4Read Capacity, US gallons, Volume instantly — no submit button needed.
- 5Need US units? Flip the SI/Imperial toggle and every field converts.
Why use Rectangular Water Tank Capacity Calculator?
- ✓Implements the standard formula — V = L × W × depth × 1000 L/m³
- ✓Reference cited on-page: Geometry; IS 3370 water-retaining structures (context)
- ✓One-click SI ⇄ Imperial toggle — values convert in place, physics stays in SI
- ✓Live worked example: the substitution recomputes from your numbers
- ✓Runs entirely in your browser — nothing uploaded, free forever
Frequently asked questions
What formula does the Rectangular Water Tank Capacity Calculator use?+
It computes V = L × W × depth × 1000 L/m³, per Geometry; IS 3370 water-retaining structures (context). The formula is displayed under the result along with a worked example substituted with your own inputs.
What should I keep in mind when using this calculator?+
Measure INSIDE faces — 230 mm walls steal ~15% from outside dimensions on a small sump. Keep 100–150 mm freeboard below the overflow when sizing usable capacity.
Does it include wastage?+
Yes — standard wastage/bulking factors are built in and stated in the formula line, so the quantity is an orderable number, not a bare geometric volume.
Is the Rectangular Water Tank Capacity Calculator free to use?+
Yes — completely free, no sign-up, no limits. It runs client-side in your browser, so inputs stay private and results are instant even on slow connections.
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