Sifrhippus was a very small equid the size of a house cat, varying from 12 to 8.5 pounds (5.4 to 3.9 kilograms), the size variance, according to one theory, depending on the warmth of the climate.
Sifrhippus a fost un ecvideu foarte mic, de mărimea unei pisici de casă, variind de la 3.9 la 5.4 kg, mărimea variației, conform unei teorii, depinzând de căldura climei.