Colby Flag

Colby

County:
Thomas County
County Seat:
Yes
Area (mi²):
3.661
State:
Kansas

Colby is a city located in Thomas County, Kansas. Colby has a 2026 population of 5,504. It is also the county seat of Thomas County. Colby is currently declining at a rate of -0.31% annually and its population has decreased by -1.87% since the most recent census, which recorded a population of 5,609 in 2020.

The median household income in Colby is $63,494 with a poverty rate of 8%. The median age in Colby is 32.3 years: 32.2 years for males, and 32.5 years for females. For every 100 females there are 99.3 males.

5.5K
Total Population
1,503
Density (mi²)
-17 -0.31%
Growth

Colby Population

Colby Population

Data after 2023 is projected based on recent change

Year ↓
Population
Growth
Annual Change
20265,504-17-0.31%
20255,521-18-0.32%
20245,539-36-0.65%
20235,575-7-0.13%
20225,582-39-0.69%
20215,621140.25%
20205,6092935.51%
20195,316230.43%
20185,293-99-1.84%
20175,392-6-0.11%
20165,398-34-0.63%
20155,432591.1%
20145,373-46-0.85%
20135,419-1-0.02%
20125,420-6-0.11%
20115,426100.18%
20105,416290.54%
20005,450541%
19905,396-148-2.67%
19805,54488619.02%
19704,65844810.64%
19604,2103519.1%
19503,85900%

Median Age

Overall: 32.3 years
Female: 32.5 years
Male: 32.2 years

Colby Adults

There are 3,950 adults, (814 of whom are seniors) in Colby.

Sex Ratio

Female: 2,703 (50.2%)
Male: 2,684 (49.8%)

Demographics

The racial composition of Colby includes 87.34% White, 3.92% other race, and smaller percentages for Black or African American, Native American and multiracial populations.

Population by Race

Race
Population ↓
Percentage (of total)
White4,70587.34%
Two or more races3927.28%
Other race2113.92%
Black or African American781.45%
Native American10.02%
Race
Population ↓
Percentage (of total)
Other race1943.6%
Two or more races1322.45%
White1172.17%
Black or African American470.87%
Race
Population ↓
Percentage (of total)
White4,58885.17%
Two or more races2604.83%
Black or African American310.58%
Other race170.32%
Native American10.02%

Colby Marital Status

Economics and Income Statistics

Colby 's average per capita income is $45,946. Household income levels show a median of $63,494. The poverty rate stands at 8%.

Families: A family includes the owner or renter of the home along with everyone related to them - whether through birth, marriage, or adoption. This includes relatives like spouses, children, parents, siblings, grandparents, and any other family members.
Households: A household includes all the people who occupy a housing unit (such as a house or apartment) as their usual place of residence.
Non Families: A nonfamily household is either someone living alone or when the owner/renter lives with people they aren't related to, like roommates.
Name
Median ↓
Mean
Married Families$109,250-
Families$97,292$100,771
Households$63,494$78,079
Non Families$35,825$43,360

$45,946

Average Income

$63,494

Median Household Income

8%

Poverty Rate

Nearby Cities

Sources

  1. US Census State Population Estimates - Most recent state estimates from the Census Bureau's Population Estimates Program
  2. US Census County Population Estimates - Most recent county estimates from the Census Bureau's Population Estimates Program
  3. American Community Survey (2009 - 2013)
  4. Census QuickFacts
  5. Historical Populations of States and Counties (1790 - 1990)