How far is Portsmouth, NH from Loudon, NH?
The driving distance from Portsmouth, NH to Loudon, NH is about 42.7 miles (68.7 km), with a travel time of about 01h 13m by car.
- The straight-line flight distance is about 38.5 miles (62 km).
- For a round trip, plan for roughly 02h 26m 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 01h 13m.
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
Sunny
Driving Route Map
The map below follows the saved road route between Portsmouth and Loudon.
Turn-by-Turn Driving Directions
Step-by-step road directions between Portsmouth and Loudon.
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1
Start on Congress Street
954 ft · 34 sec · Congress Street
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2
Turn right onto Maplewood Avenue
1.1 km · 2 min · Maplewood Avenue
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3
Turn left onto Cutts Street
139 m · 16 sec · Cutts Street
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4
Turn slight right
1 km · 1 min
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5
Exit the rotary onto NH 16 North: Concord, Rochester
2261 ft · 51 sec
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6
Take the exit straight
961 ft · 15 sec
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7
Keep slight left to continue on Spaulding Turnpike North, NH 16 North, US 4 West
1364 ft · 21 sec
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8
Merge slight left onto Spaulding Turnpike
3.8 mi · 5 min · Spaulding Turnpike
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9
Take the exit slight right toward US 4: Dover Point Road, Durham-UNH, Concord
1594 ft · 39 sec
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10
Keep slight left to continue on US 4: Durham-UNH, Concord
72 m · 8 sec
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11
Turn left
1833 ft · 52 sec
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12
Enter the roundabout and take exit 2 toward Boston Harbor Road
37 m · 3 sec · Boston Harbor Road
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13
Exit the roundabout onto Boston Harbor Road
811 ft · 22 sec · Boston Harbor Road
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14
Continue on Scammell Bridge
1132 ft · 28 sec · Scammell Bridge
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15
Continue on Piscataqua Road
8.8 mi · 14 min · Piscataqua Road
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16
Enter the roundabout and take exit 2 toward Lee Circle
48 m · 5 sec · Concord Road
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17
Exit the rotary onto Concord Road
2575 ft · 56 sec · Concord Road
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18
Continue on Old Concord Turnpike
1.8 mi · 3 min · Old Concord Turnpike
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19
Continue on Old Turnpike Road
5.1 mi · 7 min · Old Turnpike Road
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20
Continue on First New Hampshire Turnpike
7.8 mi · 13 min · First New Hampshire Turnpike
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21
Continue on Dover Road
4.3 mi · 7 min · Dover Road
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22
Enter the roundabout and take exit 2 toward Epsom Circle
81 m · 7 sec · Dover Road
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23
Exit the rotary onto Dover Road
3.1 mi · 5 min · Dover Road
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24
Turn right onto King Road
1.4 mi · 3 min · King Road
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25
Continue on Chichester Road
1.7 mi · 4 min · Chichester Road
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26
Continue on South Village Road
1.3 km · 2 min · South Village Road
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27
Arrive at your destination
0 m · 1 sec · South Village Road
Car Route Details
A richer read on the saved driving route between Portsmouth and Loudon.
Turn-heavy local drive
The route has frequent decision points for its length, so lane choice and turn timing will matter more than cruising speed.
Piscataqua Road
Continue on Piscataqua 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.
Mostly Sunny leaving Portsmouth and Sunny near Loudon.
Trip Questions
Direct answers travelers usually want before committing to the drive.
How long does it take to drive from Portsmouth to Loudon?
The road trip is about 42.7 miles (68.7 km) and usually takes 01h 13m 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 21.3 miles from Portsmouth and 21.4 miles from Loudon.
How much longer is the road route than the straight-line distance?
The direct path is about 38.5 miles (62 km), while the road route adds roughly 4.2 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 4:04 PM EDT.
How much will gas cost for this route?
Using about 28.3 MPG, regular gas is estimated at $6.48 one way or $12.97 round trip. Estimated CO2 is about 13.4 kg one way.
What should you check before leaving?
Before you leave, expect Mostly Sunny around Portsmouth and Sunny near Loudon.
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 Portsmouth and Loudon. Straight-line distance: 38.55 mi (62.04 km).
#1 Portsmouth
City in Rockingham County, New Hampshire, United States
| Population | 21,557 |
| Coordinates | 43.0770400, -70.7576600 |
| Altitude | 6 |
| Country | United States |
#2 Loudon
Town of the United States
| Population | 5,697 |
| Coordinates | 43.2856400, -71.4672900 |
| Altitude | 116 |
| Country | United States |
End: Loudon (-71.46729, 43.28564)
Estimated Travel Time
Distance: 69 km by road
| Speed | Time |
|---|---|
| 30 mph (48.3 km/h) | 01h 25m |
| 40 mph (64.37 km/h) | 01h 04m |
| 50 mph (80.47 km/h) | 00h 51m |
| 60 mph (96.56 km/h) | 00h 42m |
| 70 mph (112.65 km/h) | 00h 36m |
| 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 | $6.48 | $12.97 |
| Mid-grade | $4.88 | $7.37 | $14.75 |
| Premium | $5.34 | $8.06 | $16.12 |
| Diesel | $6.35 | $9.59 | $19.18 |
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