How far is Post Falls, ID from American Falls, ID?
The driving distance from Post Falls, ID to American Falls, ID is about 555.1 miles (893.3 km), with a travel time of about 09h 06m by car.
- The straight-line flight distance is about 394.6 miles (635.1 km).
- For a round trip, plan for roughly 18h 12m of driving time before adding stops, traffic, or weather delays.
- A comfortable departure window is usually 6:00 AM to 7:30 AM PDT.
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 09h 06m.
Starting early still helps, but most travelers will want a longer stop or an overnight stay on a route this long.
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 Lemhi County, Idaho, United States
Route Weather Snapshot
Check the forecast at both ends before you head out.
Light Rain then Showers And Thunderstorms
Driving Route Map
The map below follows the saved road route between Post Falls and American Falls.
Turn-by-Turn Driving Directions
Step-by-step road directions between Post Falls and American Falls.
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1
Start on West 10th Avenue
872 ft · 40 sec · West 10th Avenue
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2
Turn right onto North Spokane Street
2114 ft · 1 min · North Spokane Street
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3
Turn left
2024 ft · 51 sec
-
4
Merge slight left
285.1 mi · 4 hr 47 min
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5
Take the exit slight right toward I 15 South: Dillon, Idaho Falls
2694 ft · 1 min
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6
Merge slight left
244.3 mi · 3 hr 50 min
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7
Take the exit slight right toward I 86 West: Chubbuck, Twin Falls
1 km · 44 sec
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8
Continue straight
21.8 mi · 21 min
-
9
Take the exit slight right toward Aberdeen, American Falls
1.1 km · 1 min
-
10
Continue on Pocatello Avenue
1.3 km · 1 min · Pocatello Avenue
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11
Continue on Harrison Street
1352 ft · 29 sec · Harrison Street
-
12
Turn right onto Fort Hall Avenue
53 m · 13 sec · Fort Hall Avenue
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13
Turn left
53 m · 13 sec
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14
Arrive at your destination
0 m · 1 sec
Car Route Details
A richer read on the saved driving route between Post Falls and American Falls.
Long-distance drive
This route is long enough that fuel, rest stops, weather, and timing matter more than any single maneuver.
North Spokane Street
Merge slight left
285 mi · 04h 47m
Route Summary
A quick read on whether this route feels easy, ambitious, or worth planning around.
Better with a longer stop
This route is long enough that most travelers will be better off planning an overnight stay or a more deliberate stop window.
Rain leaving Post Falls and Light Rain then Showers And Thunderstorms near American Falls.
Trip Questions
Direct answers travelers usually want before committing to the drive.
How long does it take to drive from Post Falls to American Falls?
The road trip is about 555.1 miles (893.3 km) and usually takes 09h 06m in normal driving conditions.
Is this a same-day trip or an overnight route?
This route is long enough that most travelers will be better off planning an overnight stay or a more deliberate stop window.
What is the halfway point on this route?
Salmon is a useful midpoint, sitting about 277.3 miles from Post Falls and 277.8 miles from American Falls.
How much longer is the road route than the straight-line distance?
The direct path is about 394.6 miles (635.1 km), while the road route adds roughly 160.5 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 7:30 AM PDT. Starting early still helps, but most travelers will want a longer stop or an overnight stay on a route this long.
How much will gas cost for this route?
Using about 28.3 MPG, regular gas is estimated at $76.26 one way or $152.53 round trip. Estimated CO2 is about 174.1 kg one way.
Do you cross a time zone on this route?
Yes. There is about a 1 hour time difference between Post Falls and American Falls, so arrival and return times should be read in local time.
What should you check before leaving?
Before you leave, expect Rain around Post Falls and Light Rain then Showers And Thunderstorms near American Falls.
Flight Path Map
This map shows the direct air route between Post Falls and American Falls. Straight-line distance: 394.63 mi (635.09 km).
#1 Post Falls
City in Kootenai County, Idaho, United States
| Population | 36,250 |
| Coordinates | 47.7179600, -116.9515900 |
| Altitude | 665 |
| Country | United States |
#2 American Falls
City in Idaho
| Population | 4,315 |
| Coordinates | 42.7860200, -112.8544400 |
| Altitude | 1343 |
| Country | United States |
End: American Falls (-112.85444, 42.78602)
Estimated Travel Time
Distance: 893 km by road
| Speed | Time |
|---|---|
| 30 mph (48.3 km/h) | 18h 29m |
| 40 mph (64.37 km/h) | 13h 52m |
| 50 mph (80.47 km/h) | 11h 06m |
| 60 mph (96.56 km/h) | 09h 15m |
| 70 mph (112.65 km/h) | 07h 55m |
| 80 mph (129 km/h) | 06h 55m |
Fuel, Round Trip and CO2
Estimated fuel cost and emissions for this route.
| Fuel | $/gal | One way | Round trip |
|---|---|---|---|
| Regular gas | $3.89 | $76.26 | $152.53 |
| Mid-grade | $4.23 | $82.89 | $165.77 |
| Premium | $4.55 | $89.11 | $178.23 |
| Diesel | $5.41 | $106.02 | $212.04 |
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 Idaho · 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.