Calvin, OK has a population of 297 and is the 22,563rd largest city in the United States. The population density is 611 per sq mi which is 1019% higher than the Oklahoma average and 574% higher than the national average. The median age in Calvin is 29 which is approximately 19% lower than the Oklahoma average of 36. In Calvin, 60% of the population over 15 years of age are married, 98% speak English and 2% speak Spanish. 73% of Calvin residents were born in Oklahoma, 26% were born out of state, 1% were born outside of the United States and 0% were foreign born.