In general, townspeople are named burgesses in Domesday Book, though other inhabitants are occasionally recorded.
Counting urban populations is a more than usually hazardous operation. Identifying which settlements were towns is a problem in itself. Within those towns, Domesday Book often itemises houses, sites and 'plots' rather than people, and sometimes gives no population count at all. Additionally, many townspeople are described as though they were rural labourers, and it has been argued than a significant proportion of the rural population adjacent to towns were actually townspeople.
On a strict count of those described as burgesses, the urban population was 3% of the Domesday total; but this is an improbably low figure. The population of the 112 settlements identified by Darby as towns is approximately 20,000 households; after allowing for missing figures and missing towns, this might bring the total to 30,000 households, about 150,000 people, or roughly 8% of the total population. Many historians would regard this as an under-estimate. It has even been suggested that the proportion of the population living in towns in 1086 was similar to that three centuries later, about 10%.
For further information on urban populations, see H.C. Darby, Domesday England (1977); Edward Miller and John Hatcher, Medieval England: towns, commerce and crafts, 1086-1348 (1995).