Every tool on the site runs in your browser, works on a phone, and needs no account. Nothing you type is stored. Whether you are planning a fish tank or feeding a dog, the aim is the same: replace guesswork with a number you can act on.
What we do
On the aquarium side, we build focused calculators for freshwater tanks: volume, stocking, heater wattage, water changes, filter turnover, tank weight, substrate, glass thickness, salt mix, lighting and setup cost. On the dog side, we cover the everyday numbers of dog care, including daily food, raw feeding, puppy adult weight and dog age in human years. Each tool answers a single question well, with the formula and the reasoning explained on the page.
How we build the calculators
We favor clear, established formulas over rules of thumb. The aquarium stocking tool uses adult size and bioload for common species rather than the old inch per gallon rule, and the dog food tool uses the resting and maintenance energy formulas that vets rely on rather than a flat number per pound. Where a tool relies on an assumption, we state it plainly, and every result is an estimate for planning, so we say so.
How we check the math
Each formula is tested against worked examples before it goes live, and the tools are checked on small screens down to 360 pixels wide so they stay usable on any phone. If you spot a number that looks wrong, we want to hear about it. Corrections make the site better for everyone.
Who this is for
Tank and Tail is for fishkeepers setting up or running a freshwater tank and for dog owners working out feeding, growth and age. The tools are free, and you can get an answer in seconds without wading through a long article first. They are a starting point for planning, not a replacement for a vet, who should guide any medical or feeding decision for a living animal.
Want to know more or suggest a calculator we should add? Visit the contact page.