If you’re standing at the tip of Montauk Point, looking out at the Atlantic, it feels like you're at the very edge of the world. But if you just drove there from the edge of the East River, you probably feel like you’ve been driving for an eternity. That’s because the question of how long is Long Island isn't just a matter of miles on a map; it's a matter of traffic, geography, and some weird legal quirks that almost make it not an island at all.
Most people just want a number. The answer is 118 miles.
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But honestly? That number is a bit of a lie. It depends on where you start measuring, who you ask, and whether or not you count the bridges. If you take the Long Island Expressway (the LIE) from the Queens-Midtown Tunnel all the way to Riverhead, and then keep pushing through the South Fork to the lighthouse, you're going to realize that 118 miles feels a lot more like 300 when you're stuck behind a delivery truck in Hamptons traffic.
The Raw Data: Measuring 118 Miles of Coastline and Concrete
Let’s get the technical stuff out of the way first. Geographically speaking, Long Island stretches from New York Harbor out to Montauk Point. At its widest point, it’s only about 23 miles across. It’s shaped like a giant fish, or maybe a club, depending on how much coffee you've had.
Most official sources, like the U.S. Geological Survey (USGS), pin the length at 118 miles.
- Length: 118 miles (190 km)
- Width: Roughly 20–23 miles at the thickest part
- Total Area: Around 1,401 square miles
Think about that. If you stood it up on its end, Long Island would reach halfway to the International Space Station. It’s bigger than the state of Rhode Island. In fact, it's the largest island in the contiguous United States. Hawaii has some big ones, sure, but for the lower 48, this is the heavyweight champion.
Why the length feels different depending on your borough
Here is where it gets tricky for locals. When people ask how long is Long Island, they are often thinking about "Long Island" as the suburban counties of Nassau and Suffolk. They forget—or choose to ignore—that Brooklyn and Queens are technically on the island too.
If you start your odometer at the Brooklyn Bridge and drive to the Montauk Lighthouse, you’re hitting that 118-mile mark. But if you’re a "Long Islander" (meaning you live in Nassau or Suffolk), you might think the island "starts" at the Queens-Nassau border. From that border to the tip of Montauk is only about 100 miles.
It’s a point of local pride and constant debate.
The Supreme Court Said It's Not an Island
Wait, what?
Yeah, this is a real thing. In 1985, the United States Supreme Court actually ruled on this. In the case United States v. Maine, the court decided that for legal purposes regarding seabed rights, Long Island is a "penninsula."
The reasoning was basically that the East River is too shallow and narrow to truly separate it from the mainland in a way that matters for international maritime law. This was a massive deal for state taxes and who gets to control the water in the Long Island Sound. So, if you want to be a pedantic jerk at a party, the next time someone asks how long is Long Island, you can tell them it’s a 118-mile-long peninsula.
People will probably stop talking to you, but you'll be legally correct.
Navigating the Three Main Regions
To truly understand the scale of this place, you have to break it down. It’s not just one long strip of beach.
1. The Urban West (Brooklyn and Queens)
This is the "head" of the fish. It’s dense, packed with millions of people, and serves as the anchor to New York City. Even though it’s geographically part of the island, the culture is entirely different. You’ve got the high-rises of Long Island City and the brownstones of Brooklyn Heights. This section accounts for roughly the first 15 to 20 miles of the island's length.
2. The Suburban Middle (Nassau and Western Suffolk)
This is the classic "Long Island" most people see in movies. Levittown, the massive shopping malls, the endless rows of houses. This stretch is where the miles start to blur. You can drive for an hour and feel like you haven't left the same town. The Southern State Parkway and the Northern State Parkway run parallel here, cutting through the landscape like scars.
3. The East End (The Forks)
At Riverhead, the island splits like a snake's tongue.
The North Fork is quieter, full of vineyards and old fishing villages like Greenport. It’s about 30 miles long from Riverhead to Orient Point.
The South Fork is where you find the Hamptons and eventually Montauk. This is the "tail." It’s more famous, more expensive, and feels much longer because the roads are narrower and the speed limits are lower.
The "Time Distance" vs. Physical Distance
If you ask a local "how far is it to Montauk?" they won't say "118 miles." They will say "three hours if you leave at 4 AM, or six hours if you leave on a Friday afternoon."
Distance on Long Island is measured in units of pain.
The Long Island Expressway (I-495) is famously called "the world's longest parking lot." Because the island is long and thin, there aren't many ways to go east-to-west. You have the LIE, the Northern State, and the Southern State. That’s pretty much it. When one of those gets backed up—and they always do—the 118-mile length of the island starts to feel like a cross-country trek.
Real world example: Driving from the Throgs Neck Bridge to the Hamptons is about 80 miles. In any other part of the country, that’s an hour and fifteen minutes. On Long Island? If you hit the "Trade Parade" (the rush of construction trucks heading east in the morning), you're looking at two and a half hours. Easily.
Is Long Island Sinking?
While we’re talking about dimensions, we should talk about the future. The island was formed by a receding glacier at the end of the last ice age—specifically the Wisconsin glaciation. It’s basically a giant pile of sand and gravel called a terminal moraine.
Because it’s made of loose sediment, it’s susceptible to erosion. Every year, the Atlantic Ocean nibbles away at the South Shore. After Superstorm Sandy, the coastline changed significantly. Some parts of the island are technically getting "shorter" as the ocean claims the beaches. The bluffs in Montauk are retreating at a rate of about one to two feet per year.
So, in a thousand years, the answer to how long is Long Island might be "110 miles," or maybe just "a series of very small sandbars."
Why the North Shore and South Shore Feel Like Different Worlds
The length of the island creates a weird weather divide.
The South Shore is flat and sandy. It faces the open Atlantic. It’s usually a few degrees cooler in the summer because of the ocean breeze.
The North Shore is hilly and rocky, overlooking the Long Island Sound. It’s "The Gold Coast"—think The Great Gatsby.
Driving from one side to the other (the width) only takes 20-30 minutes, but the change in geography is jarring. It’s all due to how that glacier melted. The glacier stopped at the North Shore (leaving the hills) and then the meltwater washed sand down to the South Shore (creating the flat plains).
How to Actually Traverse the 118 Miles
If you're planning to see the whole thing, don't just stick to the highway.
- The LIRR (Long Island Rail Road): This is the busiest commuter railroad in North America. It runs the entire length of the island. Taking the train from Penn Station to Montauk is one of the best ways to see the changing landscape without losing your mind in traffic. It takes about 3 hours and 15 minutes.
- Route 25A: If you want the scenic route on the North Shore, this is it. It’s slow. It winds through old towns like Huntington and Stony Brook. It’s the "Old Long Island."
- The Ferries: You can actually leave the island from the "ends." There’s a ferry in Orient Point that takes you to New London, Connecticut, and a ferry in Port Jefferson that goes to Bridgeport. These are essential if you want to escape the island without driving back through the nightmare of New York City traffic.
Actionable Steps for Your Long Island Trip
Knowing how long is Long Island is only useful if you know how to handle it. Here is how you actually conquer the distance:
- Check the "Swell": If you’re heading to the South Shore beaches (Jones Beach, Robert Moses), use an app like Surfline. The length of the island means weather in Queens can be totally different from weather in Quogue.
- The 3 AM Rule: If you are driving to the East End for a weekend, leave at 3 AM or 10 PM. Anything in between is a gamble you will lose.
- Download "511NY": This is the official traffic app. Use it. The LIE can go from 65 mph to a dead stop in seconds because of a fender-bender 10 miles ahead.
- Visit the "Small" Islands: While you're exploring the length, don't forget Shelter Island and Fire Island. Fire Island is a 32-mile long barrier island off the South Shore that has no cars. It’s like a mini-version of Long Island from a hundred years ago.
- Gas Up in Nassau: Generally, gas gets more expensive the further east you go. Once you hit the Hamptons, you’re paying a "luxury tax" at the pump.
Long Island is a beast. It’s a 118-mile stretch of contradictions, from the grit of Brooklyn to the glitz of East Hampton. It’s longer than you think, more complicated than it looks on a map, and despite the traffic, absolutely worth the drive to the end. Just make sure you have a good playlist and a lot of patience.