Calculators for Pets

Age, food, or weight

The age tools convert between animal years and human years and are the reason most people arrive. The feeding tools work in the opposite direction, taking a weight and returning a daily amount, and they are sensitive to the food you are actually using because calorie density varies widely between brands. The weight converter is the small utility that sits between them when a vet has given you a figure in units you do not use.

Dog Age Calculator

for dog years to human years using the staged, size-aware approach.

Cat Age Calculator

for the same for cats, whose curve differs from a dog's.

Pet Weight Converter

for pounds and kilograms, for when the vet's figure is in the other one.

Where these calculations go wrong

The multiply-by-seven rule

One dog year does not equal seven human years. Dogs age very quickly in their first two years and then more slowly, and the rate differs by breed size, so a flat multiplier is wrong at both ends of a dog's life. These tools use the staged research-based approach instead.

Feeding by volume rather than energy

A cup of one food and a cup of another can differ substantially in calories, so a portion that is right for one bag can be wrong for the next. The feeding tools ask for the food's calorie density for that reason.

Questions about pets

Why is my dog's age different from the seven-year rule?

Because the rule is not accurate. Dogs reach something like adolescence within their first year and adulthood by roughly two, then age more gradually, and larger breeds age faster later in life. The staged approach these tools use reflects that curve rather than flattening it into one multiplier.

Related sections

• Health for the human versions of the same energy and weight arithmetic.