How far is Alton, NH from Portsmouth, NH?
The driving distance from Alton, NH to Portsmouth, NH is about 39 miles (62.8 km), with a travel time of about 00h 52m by car.
- The straight-line flight distance is about 34.7 miles (55.9 km).
- For a round trip, plan for roughly 01h 44m 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 52m.
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.
City in Strafford County, New Hampshire, United States
Route Weather Snapshot
Check the forecast at both ends before you head out.
Patchy Fog then Scattered Showers And Thunderstorms
Patchy Fog then Isolated Showers And Thunderstorms
Driving Route Map
The map below follows the saved road route between Alton and Portsmouth.
Turn-by-Turn Driving Directions
Step-by-step road directions between Alton and Portsmouth.
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1
Start on the route
102 m · 27 sec
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2
Turn right onto Main Street
1343 ft · 38 sec · Main Street
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3
Enter the roundabout and take exit 2 toward the route
605 ft · 17 sec
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4
Exit the roundabout
14.5 mi · 22 min
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5
Take the exit slight right
552 ft · 16 sec
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6
Continue on NH 16 On-Ramp South
1625 ft · 25 sec · NH 16 On-Ramp South
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7
Merge slight left onto Spaulding Turnpike
20 mi · 26 min · Spaulding Turnpike
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8
Take the exit slight left toward I 95 North
1.5 km · 2 min
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9
Enter the roundabout and take exit 3 toward Portsmouth Traffic Circle
692 ft · 20 sec
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10
Exit the rotary onto US 1 Bypass North: Portsmouth, Woodbury Avenue
1.6 km · 2 min
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11
Turn left onto Submarine Way
566 ft · 18 sec · Submarine Way
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12
Turn right onto Market Street
1 km · 2 min · Market Street
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13
At the end of the road, turn right onto Congress Street
16 m · 1 sec · Congress Street
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14
Arrive at your destination
0 m · 1 sec · Congress Street
Car Route Details
A richer read on the saved driving route between Alton 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.
Spaulding Turnpike
Merge slight left onto Spaulding Turnpike
20 mi · 00h 26m
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.
Patchy Fog then Scattered Showers And Thunderstorms leaving Alton and Patchy Fog then Isolated Showers And Thunderstorms near Portsmouth.
Trip Questions
Direct answers travelers usually want before committing to the drive.
How long does it take to drive from Alton to Portsmouth?
The road trip is about 39 miles (62.8 km) and usually takes 00h 52m 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?
Rochester is a useful midpoint, sitting about 19.1 miles from Alton and 19.9 miles from Portsmouth.
How much longer is the road route than the straight-line distance?
The direct path is about 34.7 miles (55.9 km), while the road route adds roughly 4.3 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 8:00 AM to 10:00 AM EDT. If you want a more comfortable same-day return, try to leave by 4:46 PM EDT.
How much will gas cost for this route?
Using about 28.3 MPG, regular gas is estimated at $5.44 one way or $10.89 round trip. Estimated CO2 is about 12.3 kg one way.
What should you check before leaving?
Before you leave, expect Patchy Fog then Scattered Showers And Thunderstorms around Alton and Patchy Fog then Isolated Showers And Thunderstorms near Portsmouth.
Stop Ideas Near Rochester
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 Rochester.
Dover Transportation Center
Durham–UNH station
Portsmouth, New Hampshire
Wells Regional Transportation Center
Flight Path Map
This map shows the direct air route between Alton and Portsmouth. Straight-line distance: 34.75 mi (55.93 km).
#1 Alton
Town in New Hampshire (United States)
| Population | 5,364 |
| Coordinates | 43.4523000, -71.2175700 |
| Altitude | 165 |
| 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: 63 km by road
| Speed | Time |
|---|---|
| 30 mph (48.3 km/h) | 01h 17m |
| 40 mph (64.37 km/h) | 00h 58m |
| 50 mph (80.47 km/h) | 00h 46m |
| 60 mph (96.56 km/h) | 00h 39m |
| 70 mph (112.65 km/h) | 00h 33m |
| 80 mph (129 km/h) | 00h 29m |
Fuel, Round Trip and CO2
Estimated fuel cost and emissions for this route.
| Fuel | $/gal | One way | Round trip |
|---|---|---|---|
| Regular gas | $3.95 | $5.44 | $10.89 |
| Mid-grade | $4.46 | $6.15 | $12.30 |
| Premium | $4.86 | $6.70 | $13.41 |
| Diesel | $6.00 | $8.28 | $16.55 |
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 · Jun 11, 2026
Distance to Other Cities
Planning a road trip? See the full trip guide on Trip.ovh — stops, fuel costs, weather, and departure timing.