Hydroponics tool
Reservoir Volume Calculator
Calculate tank, bucket, pot, and reservoir water volume for hydroponics, indoor growing, nutrient mixing, and irrigation planning.
Internal length of the tank.
Internal width of the tank.
Full internal height of the reservoir.
Use this to calculate current water volume, not only full capacity.
Choose the unit used for the internal dimensions.
Recommended products for this reservoir size
Water tank accessory
A useful product for this reservoir size, nutrient volume, or irrigation setup.
Water tank accessory
A useful product for this reservoir size, nutrient volume, or irrigation setup.
Water tank accessory
A useful product for this reservoir size, nutrient volume, or irrigation setup.
Internal diameter of the cylindrical tank.
Full internal height of the tank.
Water fill height inside the tank.
Choose the unit used for dimensions.
Recommended products for this tank volume
Water tank accessory
A useful product for this reservoir size, nutrient volume, or irrigation setup.
Water tank accessory
A useful product for this reservoir size, nutrient volume, or irrigation setup.
Water tank accessory
A useful product for this reservoir size, nutrient volume, or irrigation setup.
Top internal diameter of the round pot or bucket.
Bottom internal diameter. Use same value as top if sides are straight.
Internal height of the pot or bucket.
Current liquid height inside the container.
Choose the unit used for the measurements.
Recommended products for this container size
Water tank accessory
A useful product for this reservoir size, nutrient volume, or irrigation setup.
Water tank accessory
A useful product for this reservoir size, nutrient volume, or irrigation setup.
Water tank accessory
A useful product for this reservoir size, nutrient volume, or irrigation setup.
Reservoir volume calculator for hydroponics and indoor growing
This reservoir volume calculator helps growers work out how much water a hydroponic tank, nutrient reservoir, bucket, round pot, or container can hold. It is useful for nutrient mixing, irrigation planning, top-ups, water changes, dosing schedules, and day-to-day reservoir management in hydroponics, indoor growing, coco systems, and garden irrigation.
The calculator supports rectangular tanks, cylindrical reservoirs, and round pots or buckets, and it can estimate both full capacity and the current water volume based on fill height.
How this reservoir calculator works
The tool calculates internal container volume from the dimensions you enter. For partially filled reservoirs, it uses the current liquid height to estimate how much water is actually inside the tank right now.
What each parameter means
- Length / width / height: internal dimensions of a rectangular tank.
- Diameter: internal width across a cylindrical tank.
- Top diameter: top internal width of a tapered round pot or bucket.
- Bottom diameter: bottom internal width of a tapered round pot or bucket.
- Current fill height: actual water height currently inside the reservoir.
- Full capacity: maximum internal volume if the container is filled to the top.
Why reservoir volume matters
Accurate reservoir volume is important for dosing nutrients, additives, pH adjusters, enzymes, beneficial microbes, and cleaning solutions. If the volume is wrong, nutrient concentration can be too weak or too strong.
Knowing the real water volume also helps growers calculate refill size, evaporation losses, nutrient top-ups, and system maintenance more accurately.
Useful volume conversions
- 1 liter = 0.264 US gallons
- 1 liter = 0.22 UK gallons
- 1 cubic meter = 1000 liters
This calculator converts the result automatically into liters, US gallons, UK gallons, and cubic meters so growers can compare tank sizes and nutrient charts more easily.
Best practice for growers
- Measure internal dimensions, not external ones.
- Use current fill height when the reservoir is not full.
- Recheck volume after changing tank design or water level sensors.
- Use the calculated volume before mixing nutrients or additives.
- Keep a record of normal top-up volume for easier maintenance planning.
Shipping. 3 day EU delivery
7 to 15 EUR under 30kg. See more on Shipping details page.
60 days returns
You can get a refund or replacement after up to 30 days from purchase.
But we ussualy stand on customers side, so we can give a 60 days time frame!
2 months post sale expert support
It's free.
We are a team of 10 with a decade of wise expirience in growing and gardening, so if you'll have any need of help, we'll guide you to your goal within 2 months from a purchase.
About us. Our 9 year history
GoToGarden started in 2017 out of personal frustration. Our founder was a hobby grower who spent hours navigating online shops that felt built by people who had never touched a plant — cluttered layouts, vague product descriptions, no real guidance on what to actually buy or why. He knew there had to be a better way.
See more on About us page
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