Measurement
US gallons or imperial gallons? Resolve the unit before calculating
How an ambiguous gallon changes the arithmetic, and what to keep in your treatment notes.
By FishyMag · Published
Worked arithmetic example · Not a clinical review or treatment recommendation.
The word gallon is not enough
FishyMag’s calculator distinguishes a US gallon (3.785411784 litres) from an imperial gallon (4.54609 litres). Ten of each therefore represent about 37.85 and 45.46 litres respectively. Treating those volumes as equal produces about a 20% difference. These are volume conversions, not revised dosing instructions.
Do not silently repair a label
If a label includes a litre value and a rounded gallon value, record the manufacturer’s pair rather than replacing one with a more precise number and presenting that as the official instruction. If the market or unit is ambiguous, use the label photograph in a manufacturer enquiry. An online page for another market is not proof that your bottle uses the same convention.
Make the exported result understandable
Write “US gal”, “imperial gal” or “L” beside every stored volume. Keep the original input and converted value together so another keeper can reproduce the calculation. A number copied into a message without its unit cannot be reliably checked. FishyMag provides explicit unit choices; choose the one documented for the input rather than the one that produces a familiar-looking result.
Put it into practice
Your checklist
- Identify the gallon convention.
- Preserve the source’s original values and market.
- Export numbers with units, not numbers alone.
Sources and scope
This article distinguishes manufacturer statements from FishyMag’s own workflows and arithmetic examples. Linked formulation records retain their own evidence dates; publishing this article does not refresh those records.
AI-assisted writing and development. Not hands-on product testing or veterinary review. How we publish →
FishyMag reports what manufacturers say, quoted and linked. It does not diagnose illness or recommend a treatment, and it never infers that a product is safe from the absence of a warning — where no statement exists, it says so.
Formulations change. Always read the label on the bottle in your hand, and contact the manufacturer if your tank contains anything valuable or unusual.