Marsing, ID has a population of 1,536 and is the 12,540th largest city in the United States. The population density is 2,254 per sq mi which is 11712% higher than the Idaho average and 2388% higher than the national average. The median age in Marsing is 26 which is approximately 28% lower than the Idaho average of 36. In Marsing, 56% of the population over 15 years of age are married, 62% speak English and 38% speak Spanish. 48% of Marsing residents were born in Idaho, 38% were born out of state, 1% were born outside of the United States and 13% were foreign born.