Bertha, MN has a population of 539 and is the 19,110th largest city in the United States. The population density is 497 per sq mi which is 704% higher than the Minnesota average and 449% higher than the national average. The median age in Bertha is 34 which is approximately 9% lower than the Minnesota average of 38. In Bertha, 58% of the population over 15 years of age are married, 99% speak English and 0% speak Spanish. 77% of Bertha residents were born in Minnesota, 21% were born out of state, 1% were born outside of the United States and 1% were foreign born.