Aquarium Calculators

R2R Calculators

Tank Volume Salinity Correction

Tip: These calculators assume a well-mixed system. Always re-test after changes.

Tank Volume Calculator

Calculate gross volume and estimate net water after rock/sand displacement.

Tank shape

Units

Length

Width

Height

Diameter

Height

Length

Height

Back width

Front max width

Use actual water height (filled volume)

Filled height

Note

We’ll use this height instead of tank height in the calculation.

Displacement preset

Estimated displacement (%)

Net water = gross volume minus displacement.

Result

Enter dimensions and click Calculate.

Note: Displacement is an estimate. Actual water volume varies by rock type, sand depth, and equipment.

Salinity Correction Calculator

Plan RO/DI or saltwater swaps to raise/lower salinity, with step-by-step options.

Net water volume

Salinity scale

Current

Target

Saltwater mix strength

Max change per step

Planning helper — re-check salinity after each step.

Temperature note

Best practice: calibrate your refractometer with 35 ppt solution.

Result

Enter values and click Calculate.

Notes: Assumes a well-mixed system and repeatable “swap then mix” steps.