Home > NH > Rockingham County > Newmarket > Zip 03857

Zip Code 03857 — Newmarket, NH

03857 is a ZIP Code associated with Newmarket, NH, located within Rockingham. The postal region supports an estimated population of 9,463 residents across Data Pending housing units, with a population density of 290.1 people per square mile.
WorldPlaceData database updated: October 2026

📍 View location on OpenStreetMap (43.069100, -70.951640)

Data MetricLocal Statistic
Postal / Zip Code03857
Primary CityNewmarket
State / ProvinceNH
CountyRockingham
Total Population9,463
Median Household IncomeData Pending
Total Housing UnitsData Pending
Population Density290.1 people/sq mi
TimezoneAmerica/New_York

How 03857 Compares

MetricZIP 03857Rockingham CountyNH State Average
Population9,463319,0821,394,951
Median IncomeData PendingN/AN/A
Population Density290.1 /sq mi----

Nearby ZIP Codes

ZIP CodeCityDistancePopulationMedian Income
Zip 03856Newfields2.2 mi2,023N/A
Zip 03824Durham3.7 mi15,080N/A
Zip 03861Lee4.4 mi4,576N/A
Zip 03885Stratham4.5 mi7,754N/A
Zip 03840Greenland5.6 mi4,106N/A

Data Sources & Methodology: Geographic coordinates and ZIP Code assignments are derived from underlying geographic and postal datasets. Note that ZIP Codes are USPS postal delivery areas, while Census ZCTAs are statistical approximation areas. Read full methodology →