So, you’re looking at a map of the Florida Keys and thinking it’s a straight shot. On paper, the mileage from Key Largo to Key West is almost exactly 97.4 miles if you’re starting from the heart of Key Largo at Mile Marker 100 and heading down to the Southernmost Point. It sounds like a quick two-hour breeze. It isn't.
Most people treat the Overseas Highway like a standard interstate. Big mistake. You aren't just driving; you're navigating a 113-mile chain of coral islands connected by 42 bridges, including the massive Seven Mile Bridge. If you treat this drive as a race to hit a specific odometer reading, you’re basically missing the entire point of the Keys.
Honestly, the "mileage" here is measured in Mile Markers, those little green signs on the side of U.S. 1. They start at 127 just south of Florida City and count down to zero in Key West. When people talk about distance down here, they don't use street addresses. They say, "I'm at Mile Marker 82," and everyone just knows what that means.
Understanding the Actual Mileage From Key Largo to Key West
The actual distance varies slightly depending on where you start in Key Largo. Key Largo is a long island. If you’re at the northern tip near the Ocean Reef Club, you’re looking at over 100 miles. If you’re at the southern end near Tavernier, the mileage from Key Largo to Key West drops closer to 90 miles.
Geography matters. The road is a narrow ribbon of asphalt. You’ve got the Atlantic Ocean on your left and the Gulf of Mexico on your right. It’s stunning. It’s also slow. The speed limit fluctuates between 35 and 55 mph, and the Monroe County Sheriff’s Office doesn't play around. They will pull you over for doing 50 in a 45. They’ve seen enough accidents on the Two-Lane Stretch to know why speed matters.
Why the Clock Matters More Than the Odometer
Let's talk about time. In most parts of America, 97 miles takes about 90 minutes. In the Keys? Budget three hours. On a holiday weekend like Labor Day or during Fantasy Fest in October, that 97-mile trip can easily balloon into a five-hour crawl. There is only one road in and one road out. If a boat hits a bridge fender or a trailer jackknifes at Mile Marker 70, the whole chain grinds to a halt.
Think about the bridges. The Seven Mile Bridge (which is actually 6.79 miles long, but who's counting?) is the crown jewel. Driving it feels like flying over the water. You’ll see the Old Flagler Bridge—the "Old Seven"—sitting parallel to the new one. It was built by Henry Flagler’s Florida East Coast Railway back in the early 1900s. It’s a literal monument to human stubbornness against the ocean.
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Breaking Down the Segments
You’ll hit the "Middle Keys" around Islamorada. This is Mile Marker 80 territory. By the time you’ve covered 20 miles of your mileage from Key Largo to Key West, you’re already in the Sport Fishing Capital of the World. You’ll see huge marinas and places like Robbie’s of Islamorada. Stop there. Seriously. Feed the tarpon. They are massive, prehistoric-looking fish that will jump out of the water to grab a baitfish from your hand. It’s a tourist trap, sure, but it’s a classic one.
Marathon is the halfway point. It sits around Mile Marker 50. This is where you gas up if you’re worried about prices, as Key West fuel is usually the most expensive in the state. Marathon is a "real" town with grocery stores and hospitals, unlike some of the smaller, more rugged islands.
Once you cross the Seven Mile Bridge at the south end of Marathon, you enter the Lower Keys. This is where the vibe shifts. It gets quieter. More mangroves. Fewer neon signs. You’ll pass through Big Pine Key, home to the National Key Deer Refuge. The speed limit drops here, especially at night, to protect the tiny, endangered Key Deer. Don't speed through Big Pine. The deer are small—about the size of a large dog—and they have zero road sense.
The Final Stretch into Key West
The last 20 miles feel like they take the longest. You’ll pass through islands with names like Sugarloaf, Cudjoe, and Big Coppitt. You'll start to see the Naval Air Station Key West at Boca Chica. If you’re lucky, you’ll see F-18s screaming overhead.
Finally, you hit Mile Marker 0. You’ve covered the mileage from Key Largo to Key West, and you're at the end of the road. Literally. The intersection of Whitehead and Fleming Streets is where the "End 1" sign sits.
Realities of the Drive: Traffic and Hazards
Let's be real for a second. The drive can be stressful if you're in a rush. Tailgating is a huge issue on U.S. 1. You'll have locals who want to go 60 mph and tourists who are staring at the turquoise water going 30 mph. This gap creates frustration.
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- Passing Zones: They are rare. Most of the road is a solid double yellow line.
- Weather: If a heavy rainstorm hits, visibility drops to near zero instantly.
- The "Stretch": The 18-mile stretch from Florida City to Key Largo is notorious for accidents. It’s technically before the Key Largo to Key West leg, but it sets the tone for the trip.
I’ve driven this route dozens of times. The best advice? Put the phone away. Not just for safety, but because the scenery is the entire reason people pay thousands of dollars to come here. You’ll see ospreys nesting on top of power poles. You’ll see the change in water color from murky green to vibrant cerulean as the reef gets closer to the islands.
Hidden Spots Along the Way
If you just focus on the mileage from Key Largo to Key West, you'll miss Bahia Honda State Park. It's at Mile Marker 37. It has what many consider the best beach in the Keys. Most of the Keys don't actually have "beaches" in the traditional sense because the coral reef offshore prevents waves from grinding down shells into sand. Bahia Honda is the exception.
There's also No Name Pub on Big Pine Key. It’s tucked away in a residential neighborhood. The interior is covered in thousands of signed dollar bills. It’s the kind of place you won't find if you're just staring at your GPS.
Practical Logistics for the Trip
If you’re renting a car at Miami International Airport (MIA), you have about a 30-mile drive just to reach Key Largo. So your total trip to Key West is closer to 130 miles.
Most people ask: Is it better to drive or fly? Flying into Key West (EYW) saves you the drive time, but you miss the bridges. Driving gives you the freedom to stop at a roadside shack for a slice of Key Lime Pie. Always look for the pie that is yellow, not green. If it’s green, it’s fake. Real Key Lime juice is acidic and turns the pie a creamy yellow color. This is the kind of insider knowledge that makes the 97-mile trek worth it.
Gas and Electric Charging:
There are plenty of gas stations, but they get sparser in the Lower Keys. If you're driving an EV, there are Tesla Superchargers in Marathon and Key West, and various Level 2 chargers at hotels along the way. Don't let your battery get below 20% before you hit the Seven Mile Bridge, just in case there's a traffic delay.
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Actionable Next Steps for Your Journey
To make the most of the mileage from Key Largo to Key West, don't just drive—explore.
1. Download the "Monroe County Sheriff" App: This might sound weird, but it gives you real-time traffic alerts for U.S. 1. If there's a wreck, you'll know before you're trapped on a bridge.
2. Time your departure: Leave Key Largo before 9:00 AM or after 6:00 PM if you want to avoid the heaviest tourist traffic. Friday afternoons heading south and Sunday afternoons heading north are the absolute worst times to be on the road.
3. Check the wind: If you’re planning on stopping to boat or snorkel mid-way, check the marine forecast. High winds make the bridges beautiful with whitecaps, but they make the water visibility terrible for snorkeling at places like Pennekamp or Looe Key.
4. Pack a small cooler: Stop at a Publix in Key Largo. Buy water and snacks. Prices in the Lower Keys and Key West are significantly higher due to the logistics of trucking everything down that single road.
The mileage from Key Largo to Key West is short, but the experience is long. Treat it like a slow-motion tour of a Caribbean paradise rather than a commute. You'll arrive in Key West much more relaxed and ready for a sunset celebration at Mallory Square.
Make sure your spare tire is inflated. Check your coolant levels—the Florida heat is brutal on engines idling in traffic. Once you hit that Mile Marker 0 sign, you've completed one of the most iconic road trips in the world. Now go find some conch fritters and a cold drink. You earned it.