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Where Massachusetts's Population Sits: 98.2% Inside Boston's 100-Mile Reach

By SimpleMapLab·Published 13 May 2026·Rank #7 of 50 states·↑ All 50 states

98.2% of Massachusetts’s population — roughly 6.91 M of the state’s 7.04 M residents — lives within 100 miles of Boston. Massachusetts ranks #7 of 50 states for capital-to-population centrality.

Map: 100-mile geodesic radius around Boston, MA, showing the share of Massachusetts captured inside the circle.Dark forest-green stroke = the state boundary of Massachusetts. Dashed forest-green ring = the 100-mile geodesic radius around the Boston state capitol. The filled green dot marks the capitol location.Boston
A 100-mile geodesic radius around the Boston, MA state capitol overlaid on Massachusetts. 98.2% of Massachusetts's population lives inside the dashed ring.
98.2%
of Massachusetts’s population within 100 miles of Boston
6.91 M
residents inside the radius (of 7.04 M statewide)
16 mi
from Boston to Massachusetts’s population centroid
#7
of 50 states ranked by capital-to-population centrality
Open this radius in the map → /tools/map-radius-tool · Boston, MA · 100 mi
The link opens the SimpleMapLab Map Radius Tool with the 100-mile circle already drawn around the Boston capitol. Change the radius to 50, 250, or any value to compare different framings.

Why this happened

Few US states keep this share of their residents inside their capital's reach. The 100-mile radius around Boston encloses essentially all of Massachusetts's population centres — including Worcester (the largest city inside, with roughly 207K residents) — and extends almost to the population centroid itself. Massachusetts ranks #7 of 50 states for capital-to-population centrality.

The biggest cities inside the 100-mile radius

The top 5 most-populous places (by aggregated ZIP code population) sitting inside the 100-mile circle around Boston. Cities are listed by total population captured by ZIP centroids in the dataset.

#CityPopulation in radius
1Worcester207,324
2Boston154,310
3Springfield145,090
4Cambridge119,000
5Lowell118,368

The largest city outside the radius

Massachusetts’s most-populous city outside the 100-mile circle is Pittsfield, sitting 114 miles from Boston. The aggregated population of Pittsfield’s ZIP codes alone — 44,848 residents — illustrates the gap between Massachusetts’s political seat and its population centre.

How Massachusetts compares

The states ranked closest to Massachusetts on this metric. Click any to compare the radius breakdown directly.

#6 Maryland
Annapolis · 98.4% pop. captured
#8 Maine
Augusta · 96.5% pop. captured
#5 Vermont
Montpelier · 98.6% pop. captured
#9 New Hampshire
Concord · 95.5% pop. captured
#4 Rhode Island
Providence · 100.0% pop. captured

Draw it yourself

Open the 100-mile circle around Boston →

The Map Radius Tool lets you change the radius (try 50 mi for an urban-suburban question or 250 mi for “a day’s drive”), drag the centre to compare Boston’s reach with that of Worcester, or add a second circle for a side-by-side comparison.

Methodology (brief)

We took the lat/lng of the Massachusetts state capitol building (42.3601°, -71.0589°) and drew a 100-mile geodesic radius. For every ZIP code in Massachusetts, we tested whether the ZIP centroid falls inside; if so, its population counts. We then divide by Massachusetts’s total population to produce the percentage. The full methodology for all 50 states is on the hub page.

Suggested citation: SimpleMapLab (2026). 100 Miles Around Boston: How Much of Massachusetts Is Inside? Part of the State Capital Radius study. Retrieved from https://www.simplemaplab.com/studies/state-capital-radius/massachusetts. Licensed under CC-BY 4.0.