How far is St. Petersburg, FL from Key Largo, FL?
The driving distance from St. Petersburg, FL to Key Largo, FL is about 307.5 miles (494.9 km), with a travel time of about 05h 55m by car.
- The straight-line flight distance is about 231.2 miles (372.1 km).
- For a round trip, plan for roughly 11h 50m of driving time before adding stops, traffic, or weather delays.
- A comfortable departure window is usually 6:00 AM to 8:00 AM EDT.
Reverse, save, or send this route
This drive is better planned with a longer stop or an overnight stay. Copy the route link, send it to another device, or print a clean version before you head out.
This drive is better planned with a longer stop or an overnight stay.
Flight Distance
Driving Distance
Gas Cost Calculator
Leave and Arrive Planner
Pick a departure time to see your estimated arrival and same-day return window.
Drive time stays fixed at 05h 55m.
An early departure helps you fit a real stop into the day without turning the return into a late-night drive.
You are leaving earlier than the recommended window, which gives you extra margin for breaks and traffic.
Halfway Point
A useful midpoint for breaks, coffee, or meeting in the middle.
Census designated place
Route Weather Snapshot
Check the forecast at both ends before you head out.
Partly Cloudy
Slight Chance Rain Showers
Driving Route Map
The map below follows the saved road route between St. Petersburg and Key Largo.
Turn-by-Turn Driving Directions
Step-by-step road directions between St. Petersburg and Key Largo.
-
1
Start on 34th Street South
15 m · 5 sec · 34th Street South
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2
Turn right onto Central Avenue
1304 ft · 51 sec · Central Avenue
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3
Turn right onto 31st Street South
1.1 km · 1 min · 31st Street South
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4
Take the ramp slight right
2760 ft · 1 min
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5
Merge slight right
4.9 mi · 6 min
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6
Keep slight left
1406 ft · 17 sec
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7
Merge slight right onto Sunshine Skyway Bridge
13.4 mi · 15 min · Sunshine Skyway Bridge
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8
Keep slight left to continue on I 75 South: Naples
1.1 mi · 2 min
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9
Merge slight left
28 mi · 30 min
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10
Keep slight left
175.7 mi · 3 hr 8 min
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11
Take the exit slight right toward US 27: Miami, South Bay
1118 ft · 21 sec
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12
Keep slight right to continue on US 27 South: Miami
2407 ft · 59 sec
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13
Merge slight left
9.2 mi · 11 min
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14
Keep slight right
8.6 mi · 11 min
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15
Take the exit right toward Florida's Turnpike South: Homestead, Key West
1324 ft · 32 sec
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16
Merge slight left onto Homestead Extension of Florida's Turnpike
34.5 mi · 41 min · Homestead Extension of Florida's Turnpike
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17
Keep slight left
2930 ft · 1 min
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18
Merge slight left onto Dixie Highway
19.2 mi · 27 min · Dixie Highway
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19
Continue on Overseas Highway
9.3 mi · 16 min · Overseas Highway
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20
Continue on Overseas Highway
138 m · 28 sec · Overseas Highway
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21
Turn right onto Harbor Drive
94 m · 14 sec · Harbor Drive
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22
Arrive at your destination
0 m · 1 sec · Harbor Drive
Car Route Details
A richer read on the saved driving route between St. Petersburg and Key Largo.
Long-distance drive
This route is long enough that fuel, rest stops, weather, and timing matter more than any single maneuver.
I 75 South
Keep slight left
176 mi · 03h 08m
Route Summary
A quick read on whether this route feels easy, ambitious, or worth planning around.
A longer out-and-back drive
This is still possible in one day, but it becomes a long driving day. Leaving early and planning your stop window matters more here.
Partly Cloudy leaving St. Petersburg and Slight Chance Rain Showers near Key Largo.
Trip Questions
Direct answers travelers usually want before committing to the drive.
How long does it take to drive from St. Petersburg to Key Largo?
The road trip is about 307.5 miles (494.9 km) and usually takes 05h 55m in normal driving conditions.
Is this a same-day trip or an overnight route?
This is still possible in one day, but it becomes a long driving day. Leaving early and planning your stop window matters more here.
What is the halfway point on this route?
Golden Gate is a useful midpoint, sitting about 153.9 miles from St. Petersburg and 153.5 miles from Key Largo.
How much longer is the road route than the straight-line distance?
The direct path is about 231.2 miles (372.1 km), while the road route adds roughly 76.3 extra miles because roads do not follow the straight air line.
When is the best time to leave for this route?
A good departure window is usually 6:00 AM to 8:00 AM EDT. If you want a more comfortable same-day return, try to leave by 5:10 AM EDT.
How much will gas cost for this route?
Using about 28.3 MPG, regular gas is estimated at $45.01 one way or $90.01 round trip. Estimated CO2 is about 96.4 kg one way.
What should you check before leaving?
Before you leave, expect Partly Cloudy around St. Petersburg and Slight Chance Rain Showers near Key Largo.
Stop Ideas Near Golden Gate
Useful break, food, and waypoint ideas within about 15 miles of the route midpoint.
Transit and Meeting Points
Useful pickup, handoff, or rendezvous points close to Golden Gate.
Fort Myers, Florida
Port Charlotte, Florida
Flight Path Map
This map shows the direct air route between St. Petersburg and Key Largo. Straight-line distance: 231.22 mi (372.12 km).
#1 St. Petersburg
The second most populous city in Florida.
| Population | 253,693 |
| Coordinates | 27.7708600, -82.6792700 |
| Altitude | 13 |
| Country | United States |
#2 Key Largo
Census designated place in Florida, United States
| Population | 10,433 |
| Coordinates | 25.0865200, -80.4472800 |
| Altitude | 2 |
| Country | United States |
End: Key Largo (-80.44728, 25.08652)
Estimated Travel Time
Distance: 495 km by road
| Speed | Time |
|---|---|
| 30 mph (48.3 km/h) | 10h 14m |
| 40 mph (64.37 km/h) | 07h 41m |
| 50 mph (80.47 km/h) | 06h 08m |
| 60 mph (96.56 km/h) | 05h 07m |
| 70 mph (112.65 km/h) | 04h 23m |
| 80 mph (129 km/h) | 03h 50m |
Fuel, Round Trip and CO2
Estimated fuel cost and emissions for this route.
| Fuel | $/gal | One way | Round trip |
|---|---|---|---|
| Regular gas | $4.15 | $45.01 | $90.01 |
| Mid-grade | $4.60 | $49.87 | $99.73 |
| Premium | $4.90 | $53.12 | $106.24 |
| Diesel | $4.35 | $47.20 | $94.40 |
Assumes 8.3 L/100 km (about 28.3 MPG). CO2 is an estimate and varies by vehicle, fuel blend, traffic, and terrain.
Prices in Florida · May 07, 2026
Distance to Other Cities
Planning a road trip? See the full trip guide on Trip.ovh — stops, fuel costs, weather, and departure timing.