Calvin, OK has a population of 260 and is the 23,201st largest city in the United States. The population density is 535 per sq mi which is 877% higher than the Oklahoma average and 490% higher than the national average. The median age in Calvin is 33 which is approximately 10% lower than the Oklahoma average of 36. In Calvin, 58% of the population over 15 years of age are married, 98% speak English and 2% speak Spanish. 75% of Calvin residents were born in Oklahoma, 25% were born out of state, 0% were born outside of the United States and 0% were foreign born.