What is Manhattan's block size and why does it matter?

The 1811 Commissioners' Plan set Manhattan blocks at 264 feet (short side) and 900 feet (long side). This geometry creates 124 intersections per square mile. Over two centuries of urban change, the block size remains the single best predictor of walkability.

How does Manhattan's intersection density compare to suburbs?

Manhattan: 124 intersections per square mile. Suburban grid (typical postwar development): 38 per square mile. Portland: 168 per square mile. Higher intersection density means shorter distances between destinations and more route options.

How many destinations are reachable in a 5-minute walk from a Manhattan block versus a suburb?

Manhattan: 14 destinations. Suburb: 2 destinations. A 10-minute walk from Manhattan reaches 38 destinations; from a suburb, 6. The difference is network density and mixed-use zoning, both enabled by the 264-foot block.

Do cities with smaller blocks walk more than cities with larger blocks?

Yes. Block size is the most reliable predictor of walking trips across US cities. Smaller blocks (200-300 feet) correlate with 30-50 percent higher walking rates than larger blocks (500+ feet), holding income and density constant.

Can modern cities adopt the Manhattan block size?

Some do. Portland's downtown uses roughly 200-foot blocks. New Urbanist developments target 250-300 feet. Retrofitting existing suburbs to smaller blocks requires acquiring private land, which is expensive and politically difficult.

What Manhattan knows about block size. 264 feet, since 1811.

The 1811 Commissioners' Plan of Manhattan set the short side of a block at 264 feet. Two centuries later, that number remains the single best predictor of whether a street can be walked.

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