About the Aquarium Salt Dosage Calculator
Salt needed for a marine tank or a freshwater salt treatment, at any concentration.
Also known as: marine salt calculator, aquarium salt dose, salinity calculator, specific gravity salt.
How to use this calculator
- Enter purpose, water volume.
- The result updates instantly as you type — press Calculate (or Enter) at any time.
- Review the breakdown shown under the main result.
- Use Copy result or Share to save the answer or send a link with your inputs.
Formula
salt = target concentration × water volume
Worked example
Using the values pre-filled in the calculator above:
- Purpose: Marine tank
- Water volume = 200 litres
- Target salinity = 35 ppt
the calculator returns:
- Salt needed: 7 kg
- In grams: 7,000
- Dose rate: 35 g/L
- Specific gravity: 1.0263