Dog Size Calculator: classify extra small to giant
Dog size categories in one place
This calculator classifies a dog into a practical size category used in many everyday contexts, such as general nutrition sizing, accessory sizing labels, and broad planning. It combines weight and height at the shoulder to produce a final category and a quick proportion check.
Inputs and unit conversions
You can enter values in either metric or imperial units. The calculator converts everything internally to metric using:
\(\text{lb} = \text{kg} \times 2.20462\)
\(\text{in} = \text{cm} \div 2.54\)
Height-based proxy weight
Dogs with the same shoulder height can still vary in build. To ensure height meaningfully contributes to the final result, the calculator computes a height-based proxy weight using a simple geometric scaling idea:
\[W_h = k \times H_m^3\]
Where \(H_m = \frac{H_{cm}}{100}\) and \(k = 150\). This creates a reasonable “size signal” from height without relying on breed-specific tables.
Final size score
The calculator combines the measured weight \(W\) and the height proxy \(W_h\) into a single equivalent weight:
\[W_c = \frac{W + W_h}{2}\]
The final category is selected by placing \(W_c\) into the reference size ranges shown in the table.
Proportion check
In addition to the final category, the calculator compares the measured weight \(W\) to the height proxy \(W_h\). If the ratio \( \frac{W}{W_h} \) is very high or very low, the result is flagged as “heavier” or “lighter” than typical for that height. This is not a medical assessment; it is a practical signal to re-check units and measurements or to consider breed build differences.
Practical notes
Border values are approximate because real dogs vary widely in body shape. If your dog sits right on a boundary, a different brand or guideline might place them in the adjacent category, which is why the reference table is included and highlighted for transparency.