How far is Allenstown, NH from Portsmouth, NH?
The driving distance from Allenstown, NH to Portsmouth, NH is about 41.9 miles (67.4 km), with a travel time of about 00h 55m by car.
- The straight-line flight distance is about 33.1 miles (53.3 km).
- For a round trip, plan for roughly 01h 51m 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 00h 55m.
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.
Place in New Hampshire, United States
Route Weather Snapshot
Check the forecast at both ends before you head out.
Mostly Sunny
Driving Route Map
The map below follows the saved road route between Allenstown and Portsmouth.
Turn-by-Turn Driving Directions
Step-by-step road directions between Allenstown and Portsmouth.
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1
Start on the route
21 m · 12 sec
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2
Turn left onto Gilbert Road
936 ft · 41 sec · Gilbert Road
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3
Turn sharp left onto Deerfield Road
665 ft · 22 sec · Deerfield Road
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4
Turn right onto Pinewood Road
575 ft · 10 sec · Pinewood Road
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5
Continue on Route 28
1.3 mi · 2 min · Route 28
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6
Continue on Suncook Valley Highway
4.3 mi · 7 min · Suncook Valley Highway
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7
Enter the roundabout and take exit 1 toward Epsom Circle
11 m · 1 sec · Dover Road
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8
Exit the rotary onto Dover Road
4.3 mi · 7 min · Dover Road
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9
Continue on First New Hampshire Turnpike
7.8 mi · 13 min · First New Hampshire Turnpike
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10
Continue on Old Turnpike Road
5.1 mi · 7 min · Old Turnpike Road
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11
Continue on Old Concord Turnpike
1.8 mi · 3 min · Old Concord Turnpike
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12
Continue on Concord Road
2565 ft · 56 sec · Concord Road
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13
Enter the roundabout and take exit 2 toward Lee Circle
50 m · 5 sec · Concord Road
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14
Exit the rotary onto Concord Road
8.9 mi · 14 min · Concord Road
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15
Continue on Scammell Bridge
1132 ft · 28 sec · Scammell Bridge
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16
Continue on Boston Harbor Road
812 ft · 22 sec · Boston Harbor Road
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17
Enter the roundabout and take exit 2 toward the route
54 m · 4 sec
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18
Exit the roundabout
684 ft · 17 sec
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19
Take the exit slight right
2827 ft · 1 min
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20
Merge slight left onto Spaulding Turnpike
3.5 mi · 5 min · Spaulding Turnpike
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21
Take the exit slight left toward I 95 North
1.5 km · 2 min
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22
Enter the roundabout and take exit 3 toward Portsmouth Traffic Circle
692 ft · 20 sec
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23
Exit the rotary onto US 1 Bypass North: Portsmouth, Woodbury Avenue
1.6 km · 2 min
-
24
Turn left onto Submarine Way
566 ft · 18 sec · Submarine Way
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25
Turn right onto Market Street
1 km · 2 min · Market Street
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26
At the end of the road, turn right onto Congress Street
16 m · 1 sec · Congress Street
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27
Arrive at your destination
0 m · 1 sec · Congress Street
Car Route Details
A richer read on the saved driving route between Allenstown and Portsmouth.
Highway-focused drive
Most of the mileage stays on named highways, so the important moments are ramps, exits, merges, and the final local approach.
Concord Road
Exit the rotary onto Concord Road
8.85 mi · 00h 14m
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.
Sunny leaving Allenstown and Mostly Sunny near Portsmouth.
Trip Questions
Direct answers travelers usually want before committing to the drive.
How long does it take to drive from Allenstown to Portsmouth?
The road trip is about 41.9 miles (67.4 km) and usually takes 00h 55m 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?
Northwood is a useful midpoint, sitting about 20.8 miles from Allenstown and 21 miles from Portsmouth.
How much longer is the road route than the straight-line distance?
The direct path is about 33.1 miles (53.3 km), while the road route adds roughly 8.8 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 4:38 PM EDT.
How much will gas cost for this route?
Using about 28.3 MPG, regular gas is estimated at $6.36 one way or $12.71 round trip. Estimated CO2 is about 13.2 kg one way.
What should you check before leaving?
Before you leave, expect Sunny around Allenstown and Mostly Sunny near Portsmouth.
Stop Ideas Near Northwood
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 Northwood.
Durham–UNH station
Dover Transportation Center
Exeter station
Concord, New Hampshire
Flight Path Map
This map shows the direct air route between Allenstown and Portsmouth. Straight-line distance: 33.1 mi (53.27 km).
#1 Allenstown
Town in New Hampshire
| Population | 4,488 |
| Coordinates | 43.1567300, -71.4047800 |
| Altitude | - |
| Country | United States |
#2 Portsmouth
City in Rockingham County, New Hampshire, United States
| Population | 21,557 |
| Coordinates | 43.0770400, -70.7576600 |
| Altitude | 6 |
| Country | United States |
End: Congress Street (-70.757617, 43.077054)
Estimated Travel Time
Distance: 67 km by road
| Speed | Time |
|---|---|
| 30 mph (48.3 km/h) | 01h 23m |
| 40 mph (64.37 km/h) | 01h 02m |
| 50 mph (80.47 km/h) | 00h 50m |
| 60 mph (96.56 km/h) | 00h 41m |
| 70 mph (112.65 km/h) | 00h 35m |
| 80 mph (129 km/h) | 00h 31m |
Fuel, Round Trip and CO2
Estimated fuel cost and emissions for this route.
| Fuel | $/gal | One way | Round trip |
|---|---|---|---|
| Regular gas | $4.29 | $6.36 | $12.71 |
| Mid-grade | $4.88 | $7.23 | $14.46 |
| Premium | $5.34 | $7.90 | $15.80 |
| Diesel | $6.35 | $9.40 | $18.80 |
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 New Hampshire · Oct 15, 2026