How far is Mercersburg, PA from Allentown, PA?
The driving distance from Mercersburg, PA to Allentown, PA is about 152.7 miles (245.7 km), with a travel time of about 02h 35m by car.
- The straight-line flight distance is about 138.3 miles (222.5 km).
- For a round trip, plan for roughly 05h 11m of driving time before adding stops, traffic, or weather delays.
- A comfortable departure window is usually 8:00 AM to 10:00 AM EDT.
Reverse, save, or send this route
This route works well as a day trip with time at the destination. Copy the route link, send it to another device, or print a clean version before you head out.
This route works well as a day trip with time at the destination.
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 02h 35m.
A morning start gives you useful time at the destination and keeps the return out of the late evening.
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.
Chance Rain Showers
Chance Rain Showers
Driving Route Map
The map below follows the saved road route between Mercersburg and Allentown.
Turn-by-Turn Driving Directions
Step-by-step road directions between Mercersburg and Allentown.
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1
Start on JEB Stuart Alley
38 m · 14 sec · JEB Stuart Alley
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2
Turn left onto East Seminary Street
71 m · 21 sec · East Seminary Street
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3
Turn left onto South Main Street
1946 ft · 1 min · South Main Street
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4
Continue on Buchanan Trail West
9.6 mi · 14 min · Buchanan Trail West
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5
Continue on West Baltimore Street
1.5 km · 3 min · West Baltimore Street
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6
Continue on Buchanan Trail East
1447 ft · 40 sec · Buchanan Trail East
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7
Turn left onto I 81 North: Chambersburg
1043 ft · 25 sec
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8
Merge slight left
59.3 mi · 1 hr 11 min
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9
Take the exit slight right toward US 11, US 15: Enola, Marysville
931 ft · 14 sec
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10
Keep slight left to continue on US 11 North, US 15 North: Marysville
1828 ft · 28 sec
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11
Keep slight left
2072 ft · 32 sec
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12
Merge slight left onto George N. Wade Memorial Bridge
1.2 km · 1 min · George N. Wade Memorial Bridge
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13
Continue on American Legion Memorial Highway
3.4 mi · 5 min · American Legion Memorial Highway
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14
Keep slight left to continue on American Legion Memorial Highway
19.1 mi · 23 min · American Legion Memorial Highway
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15
Take the exit slight right toward I 78 East: Allentown
1.1 km · 45 sec
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16
Continue on 78th Division Highway
7.6 mi · 9 min · 78th Division Highway
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17
Continue on William Penn Highway
42.8 mi · 51 min · William Penn Highway
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18
Keep slight right to continue on Lehigh Valley Thruway
1.5 km · 1 min · Lehigh Valley Thruway
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19
Take the exit slight right toward Cetronia
1053 ft · 27 sec
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20
Turn straight onto Tilghman Street
4.9 mi · 8 min · Tilghman Street
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21
Arrive at your destination
0 m · 1 sec · Tilghman Street
Car Route Details
A richer read on the saved driving route between Mercersburg and Allentown.
Highway-focused drive
Most of the mileage stays on named highways, so the important moments are ramps, exits, merges, and the final local approach.
I 81 North
Merge slight left
59.3 mi · 01h 11m
Route Summary
A quick read on whether this route feels easy, ambitious, or worth planning around.
A comfortable day-trip route
This route works well as a day trip. You can leave in the morning, spend meaningful time at the destination, and still return the same day.
Chance Rain Showers leaving Mercersburg and Chance Rain Showers near Allentown.
Trip Questions
Direct answers travelers usually want before committing to the drive.
How long does it take to drive from Mercersburg to Allentown?
The road trip is about 152.7 miles (245.7 km) and usually takes 02h 35m in normal driving conditions.
Is this a same-day trip or an overnight route?
This route works well as a day trip. You can leave in the morning, spend meaningful time at the destination, and still return the same day.
What is the halfway point on this route?
Colonial Park is a useful midpoint, sitting about 75.9 miles from Mercersburg and 76.7 miles from Allentown.
How much longer is the road route than the straight-line distance?
The direct path is about 138.3 miles (222.5 km), while the road route adds roughly 14.4 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 8:00 AM to 10:00 AM EDT. If you want a more comfortable same-day return, try to leave by 1:18 PM EDT.
How much will gas cost for this route?
Using about 28.3 MPG, regular gas is estimated at $22.02 one way or $44.05 round trip. Estimated CO2 is about 47.9 kg one way.
What should you check before leaving?
Before you leave, expect Chance Rain Showers around Mercersburg and Chance Rain Showers near Allentown.
Stop Ideas Near Colonial Park
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 Colonial Park.
Harrisburg Transportation Center
Middletown
Elizabethtown station
Mount Joy
Flight Path Map
This map shows the direct air route between Mercersburg and Allentown. Straight-line distance: 138.26 mi (222.51 km).
#1 Mercersburg
Borough of Pennsylvania
| Population | 1,527 |
| Coordinates | 39.8278700, -77.9033300 |
| Altitude | 173 |
| Country | United States |
#2 Allentown
The third most populous city in Pennsylvania.
| Population | 121,470 |
| Coordinates | 40.6084300, -75.4901800 |
| Altitude | 103 |
| Country | United States |
End: Tilghman Street (-75.490007, 40.608068)
Estimated Travel Time
Distance: 246 km by road
| Speed | Time |
|---|---|
| 30 mph (48.3 km/h) | 05h 05m |
| 40 mph (64.37 km/h) | 03h 48m |
| 50 mph (80.47 km/h) | 03h 03m |
| 60 mph (96.56 km/h) | 02h 32m |
| 70 mph (112.65 km/h) | 02h 10m |
| 80 mph (129 km/h) | 01h 54m |
Fuel, Round Trip and CO2
Estimated fuel cost and emissions for this route.
| Fuel | $/gal | One way | Round trip |
|---|---|---|---|
| Regular gas | $4.09 | $22.02 | $44.05 |
| Mid-grade | $4.60 | $24.79 | $49.58 |
| Premium | $4.95 | $26.70 | $53.40 |
| Diesel | $5.98 | $32.23 | $64.46 |
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 Pennsylvania · Apr 23, 2026
Distance to Other Cities
Planning a road trip? See the full trip guide on Trip.ovh — stops, fuel costs, weather, and departure timing.