|Liberty County and the state of Georgia|
|• Total||0.8 sq mi (2.1 km2)|
|• Land||0.8 sq mi (2.1 km2)|
|• Water||0 sq mi (0 km2)|
|Elevation||79 ft (24 m)|
|• Density||341.3/sq mi (130/km2)|
|Time zone||Eastern (EST) (UTC-5)|
|• Summer (DST)||EDT (UTC-4)|
|GNIS feature ID||0331886|
Gumbranch is located at .(31.838765, -81.684384)
According to the United States Census Bureau, the city has a total area of 0.8 square miles (2.1 km2), of which, 0.8 square miles (2.1 km2) of it is land and 1.23% is water.
As of the census of 2000, there were 273 people, 100 households, and 76 families residing in the city. The population density was 341.7 people per square mile (131.8/km²). There were 129 housing units at an average density of 161.4 per square mile (62.3/km²). The racial makeup of the city was 91.58% White, 5.86% African American, 2.20% Asian, 0.37% from other races. Hispanic or Latino of any race were 1.10% of the population.
There were 100 households out of which 34.0% had children under the age of 18 living with them, 60.0% were married couples living together, 9.0% had a female householder with no husband present, and 24.0% were non-families. 22.0% of all households were made up of individuals and 7.0% had someone living alone who was 65 years of age or older. The average household size was 2.73 and the average family size was 3.17.
In the city the population was spread out with 28.9% under the age of 18, 11.7% from 18 to 24, 28.9% from 25 to 44, 24.5% from 45 to 64, and 5.9% who were 65 years of age or older. The median age was 30 years. For every 100 females there were 105.3 males. For every 100 females age 18 and over, there were 98.0 males.
The median income for a household in the city was $35,625, and the median income for a family was $40,938. Males had a median income of $30,625 versus $17,917 for females. The per capita income for the city was $13,158. About 19.7% of families and 24.6% of the population were below the poverty line, including 28.6% of those under the age of eighteen and 46.2% of those sixty five or over.