Butler, NJ has a population of 7,773 and is the 4,807th largest city in the United States. The population density is 3,822 per sq mi which is 382111% higher than the New Jersey average and 4119% higher than the national average. The median age in Butler is 38 which is approximately 5% lower than the New Jersey average of 40. In Butler, 54% of the population over 15 years of age are married, 78% speak English and 14% speak Spanish. 64% of Butler residents were born in New Jersey, 16% were born out of state, 1% were born outside of the United States and 18% were foreign born.