AquaPulse Tools · Free web calculator
Medication Dosing Calculator
Work out the exact dose for your aquarium from your product's own label instructions — no mental maths, no guessing. Enter what the label says and your tank's volume, and this tool scales one to the other. It doesn't choose a medication or a treatment for you; that stays your product's own instructions and, where needed, a qualified specialist's call.
Medication dose calculator
Always follow your medication's full manufacturer instructions. This calculator only scales your product's stated label dose to your tank — it doesn't diagnose a condition or recommend a treatment. Anything specific to your medication (active ingredient, species safety, carbon removal, aeration) stays with the label or a qualified specialist.
Your results
See a worked example
Common medication-dosing mistakes
- Estimating tank volume from tank dimensions in your head. Confirm your actual volume with our Aquarium Calculator first — substrate, décor and water level all reduce it below the tank's nominal size.
- Dosing for the whole system when treating in a separate quarantine tank, or vice versa — use the volume of whichever tank the medication is actually going into.
- Applying a reduced-dose fraction that isn't actually on your product's own label, rather than one the manufacturer specifically states for your situation.
- Assuming a different product's label dose applies to yours. Concentration and formulation genuinely vary between brands — always use your own product's own label.
- Stacking multiple medications without manufacturer or specialist confirmation they're safe together. This calculator scales one product at a time and can't check interactions.
What this calculator is — and isn't
This tool has one job: turning "the label says X amount per Y litres or gallons" into the equivalent amount for your tank's actual volume. It holds no database of medications, doses or active ingredients, and doesn't infer a dose from a disease, symptom, species, invertebrate or plant — that judgement stays with your product's own manufacturer instructions, or a qualified specialist if you're unsure.
Not yet sure what you're treating? Our Emergency Diagnosis tool and Fish Symptoms hub are better starting points than this calculator.
How AquaPulse helps
Today's dose is one calculation. Remembering exactly which day of a multi-day course you're on, a week in, is a different problem — and the one that tends to slip once the first dose is behind you.
AquaPulse works from what you enter — it doesn't dose your tank or track a treatment course automatically. Logging your readings and notes across a treatment period keeps that record in one place, against what you actually did rather than memory. Get AquaPulse on the App Store or Google Play to try it.
Keep going
Related tools and guides
Common questions
Frequently asked questions
Does this calculator tell me what medication to use?
No. This tool doesn't know what any medication is, doesn't recommend a product, and doesn't diagnose a condition. It performs one calculation: scaling the dose your product's own label states to your actual aquarium volume. Choosing a treatment is a separate decision that depends on what you're treating, your species, your invertebrates and plants, and your product's own manufacturer instructions.
Why isn't there a dropdown to pick my medication?
Deliberately. This calculator doesn't hold a database of medications, active ingredients or doses, and never will — dosing genuinely varies between brands, formulations and concentrations, and presenting a fixed figure for a named product would risk being wrong or outdated. Instead, you enter the dose and reference volume printed on your own product's label, and the calculator scales that to your tank.
Is it safe to dose based on this calculator alone?
This calculator only checks your arithmetic — it doesn't check whether the product, the dose, or the timing is appropriate for your fish, invertebrates, plants or filtration. Always read your product's full manufacturer instructions, including any species-specific warnings, before dosing anything. Some treatments require removing carbon from your filter or increasing aeration; this calculator won't tell you that your specific product needs it.
Can I dose a fraction of the label amount, like a half dose?
Only if your own product's label or manufacturer specifically says a reduced dose is appropriate for your situation — for example, some products state a lower dose for scaleless fish or invertebrates. The optional dose-fraction field lets you apply a fraction your label already specifies; this calculator doesn't suggest, default to, or invent a fraction on its own.
Can I combine this with other medications?
Not unless the manufacturer of one of the products, or a qualified aquatic specialist, has explicitly confirmed the combination is safe. Combining medications can have unpredictable effects on livestock and on your biological filtration, and this calculator has no way of checking interactions between products — it only scales the single dose you enter.
How this calculator works: the result is your label dose amount, multiplied by (your tank volume ÷ the label's reference volume), multiplied by any dose fraction you've entered — pure ratio scaling, with no medication-specific data built in. Volume unit conversions use exact published constants (1 US gallon = 3.785411784 litres, 1 UK gallon = 4.54609 litres). Nothing you enter is saved or sent anywhere.
What we deliberately left out: any list or database of medications, active ingredients or doses; any suggestion of which product to use for a given condition; and any dose-fraction default or recommendation — all of that depends on your specific product and situation in ways this calculator isn't positioned to judge.
Sources and editorial information
- Published
- 7 August 2026
- Last reviewed
- 7 August 2026
- Written and maintained by
- AquaPulse (Valeon Labs Ltd)
This calculator and its supporting content are written and maintained by the AquaPulse team at Valeon Labs Ltd. The arithmetic uses only the figures you enter from your own product's label and your own tank's volume — there is no built-in medication data of any kind. We'll update this page if we find something we've got wrong.
Good to know: This tool provides arithmetic assistance only. It is not a veterinary service, does not diagnose or recommend treatment, and does not replace your product's own manufacturer instructions or specialist aquatic-health advice.