You’re sitting in a rental car at Miami International Airport, the AC is blasting against the humid Florida heat, and you’re looking at Google Maps. You want to know how many miles is it from Miami to Key West because, honestly, you’ve heard conflicting stories. Some people say it’s a quick afternoon jaunt. Others talk about it like it's a cross-country odyssey through the middle of the ocean.
The short answer? It is roughly 165 miles from downtown Miami to the Southernmost Point buoy.
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But distance in the Florida Keys is a liar. If you just look at the odometer, you’re missing the point entirely. Driving the Overseas Highway (US-1) isn't about the raw mileage; it’s about the Mile Markers, the drawbridges, and the fact that a single broken-down chicken truck in Islamorada can turn a three-hour drive into a five-hour test of your soul.
Mapping Out the Miles
Let’s get technical for a second. If you start your timer at Miami International Airport (MIA) and head south, you’re looking at about 160 to 165 miles depending on whether you take the Florida Turnpike or the slower, stop-light-heavy US-1 through Homestead.
Most travelers prefer the "Stretch." That’s the 18-mile span of US-1 that connects Florida City to Key Largo. Once you hit Key Largo, you’ve officially entered the Keys, but you’re still over 100 miles away from a margarita at Sloppy Joe’s.
It's weird. You’ll see signs for Key West early on, but the progression feels glacial because the speed limits fluctuate wildly. One minute you're doing 55 mph over turquoise water, the next you're slowing to 35 mph because a Key Deer might decide to hop across the road in Big Pine Key.
Why the "113" Number Matters
You’ll often hear people say the trip is 113 miles. They aren't wrong, but they're usually talking about the Overseas Highway specifically—the portion of US-1 that starts at the end of the mainland and runs to the end of the island chain.
- The Mainland Leg: Miami to Florida City is about 30-35 miles.
- The Keys Leg: Florida City to Key West is approximately 127 miles.
So, when you're calculating how many miles is it from Miami to Key West, make sure you’re accounting for that transition through the Everglades-adjacent suburbs of South Miami. It adds up.
The Seven Mile Bridge and Beyond
You haven't really "driven to Key West" until you’ve hit the Seven Mile Bridge. It’s exactly what it sounds like. Sorta.
Actually, the "new" bridge is technically 6.79 miles long. It connects Knight's Key (part of Marathon) to Little Duck Key. Driving it feels like flying. There’s no shoulder. Just you, concrete, and the Gulf of Mexico on one side with the Atlantic on the other.
The mileage here feels different. On a highway in Kansas, seven miles is a blink. On the Seven Mile Bridge, it’s a panoramic experience that makes you realize just how isolated these islands actually are. You’re literally driving over open water on a path that Henry Flagler’s engineers originally cleared for a railroad over a century ago.
Navigating the Mile Markers
Forget GPS for a minute. In the Keys, everyone uses Mile Markers (MM).
Key West is MM 0.
Key Largo is roughly MM 108.
Miami is way off the scale.
If you’re looking for a specific restaurant or a hidden beach, the local will tell you, "It's at MM 82, bayside." "Bayside" means the right side if you're heading south (the Gulf side), and "Oceanside" means the left (the Atlantic). It’s a simple system that makes the distance feel manageable. It turns a 165-mile journey into a series of small victories as the numbers on those little green signs slowly tick down toward zero.
Traffic: The Variable That Ruins Math
If you drive those 165 miles on a Tuesday morning in October, you’ll breeze through in about three hours and fifteen minutes.
If you try it on a Friday afternoon in February? God help you.
The "distance" becomes irrelevant. The bottleneck in Islamorada is legendary. Since there is essentially only one road in and one road out, any construction or minor accident creates a "parking lot" effect. I’ve seen that 165-mile trip take six hours during a holiday weekend.
Then there's the Seven Mile Bridge. If it closes due to an accident, you aren't going anywhere. There are no detours. You are on a ribbon of asphalt surrounded by salt water. You just wait.
Hidden Stops That Make the Miles Worth It
Don’t just blast through the miles. That’s a rookie mistake. If you’re asking how many miles is it from Miami to Key West, you should also be asking where to stop so you don't lose your mind.
Robert Is Here (Homestead)
Technically just before the Keys officially start. Get a milk shake. Trust me. The guanabana or key lime shakes are world-class. It’s a fruit stand that turned into a landmark.
Alabama Jack’s (Card Sound Road)
If you take the "toll" route (Card Sound Road) instead of the main "Stretch," you’ll find this dive bar. It’s built on barges in the mangroves. It’s greasy, loud, and perfect. It adds about 10-15 miles to your total trip, but it’s the "real" Florida.
The Rain Barrel Village (Islamorada)
You’ll know it by the giant lobster statue out front. Her name is Betsy. She’s 30 feet tall. It’s a great spot to stretch your legs and realize you’ve still got about 80 miles to go.
Bahia Honda State Park (MM 37)
This is where the mileage starts to feel like a reward. The beaches here are some of the only "natural" feeling beaches in the Keys (most others are rocky or man-made). You can see the old, broken railway bridge standing parallel to the new one.
Is the Distance Different by Boat?
Actually, yes. If you’re lucky enough to have a boat, the nautical distance is shorter because you aren't following the winding path of the islands. From Government Cut in Miami to Key West Harbor, it's roughly 130 to 140 nautical miles.
However, unless you’re on a go-fast boat, it’s going to take you a lot longer than three hours. Most cruisers take two days, stopping in Elliot Key or Rodriguez Key along the way.
Why Do People Get the Mileage Wrong?
The confusion usually stems from where "Miami" starts. If you’re in North Miami Beach or Aventura, add another 20 miles. If you’re in the Redlands, you’re already halfway to the start of the islands.
Also, the Florida Keys Overseas Heritage Trail exists for bikers and hikers. If you’re crazy enough to bike the distance, you’re looking at about 106 miles of paved trail from Key Largo to Key West. It doesn't follow the road exactly, often veering off onto old bridge segments, which changes the total distance traveled.
Logistics and Planning
When you're prepping for this drive, don't just fuel up the car. Fuel up yourself.
- Gas Prices: They rise the further south you go. Fill up in Florida City or Homestead before you hit the "Stretch." You’ll save 40 to 60 cents a gallon.
- The Deer Factor: In the Lower Keys (around Big Pine), the speed limit drops to 45 mph during the day and 35 mph at night. This is strictly enforced to protect the endangered Key Deer. Getting a ticket here is a rite of passage you don't want.
- Sunscreen: Even inside a car, that Florida sun hitting your left arm through the window for four hours will leave you with a "driver's tan."
Actionable Steps for the Drive
If you are planning to tackle these 165 miles, here is the most efficient way to do it without losing your cool.
Check the Wind: If the winds are sustained over 20 mph, the bridges can get sketchy, especially if you’re in a high-profile vehicle like an SUV or an RV.
Download Offline Maps: Cell service is generally good, but there are "dead zones" in the mangroves between Florida City and Key Largo. Having the map offline ensures you don't miss the turn for Card Sound Road.
Time Your Departure: Leave Miami before 7:00 AM or after 7:00 PM. If you try to leave at 4:00 PM on a weekday, you will spend two hours just getting out of Miami-Dade County.
The Return Trip: Everyone leaves Key West at the same time (usually 11:00 AM checkout). If you can stay an extra half-day and leave at 6:00 PM, you’ll have the road mostly to yourself.
The Tolls: Use a SunPass. Most of the tolls on the Florida Turnpike and the Card Sound Bridge are electronic-only. If you don't have one, your rental car company will hit you with "administrative fees" that cost way more than the toll itself.
At the end of the day, the number of miles is just a statistic. Whether it's 160 or 170 miles depending on your specific starting point, the journey is the actual event. Once you see the water turn that specific shade of electric blue near Marathon, you won't be looking at your odometer anymore. You'll be looking for a place to park and jump in.