How far is Post Falls, ID from Idaho Falls, ID?
The driving distance from Post Falls, ID to Idaho Falls, ID is about 490.4 miles (789.3 km), with a travel time of about 07h 18m by car.
- The straight-line flight distance is about 377.7 miles (607.9 km).
- For a round trip, plan for roughly 14h 37m 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 07h 18m.
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.
Partly Sunny
Mostly Sunny then Slight Chance Light Rain
Driving Route Map
The map below follows the saved road route between Post Falls and Idaho Falls.
Turn-by-Turn Driving Directions
Step-by-step road directions between Post Falls and Idaho 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
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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
198 mi · 3 hr 6 min
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7
Take the exit slight right toward I 15 Business, US 20 West: Historic Downtown, Arco
1619 ft · 47 sec
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8
Continue on West Broadway Street
2164 ft · 54 sec · West Broadway Street
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9
Turn right onto South Utah Avenue
2435 ft · 50 sec · South Utah Avenue
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10
Enter the roundabout and take exit 1 toward South Utah Avenue
31 m · 2 sec · South Utah Avenue
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11
Exit the roundabout onto South Utah Avenue
781 ft · 23 sec · South Utah Avenue
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12
Turn left onto Pancheri Drive
1930 ft · 43 sec · Pancheri Drive
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13
Continue on West 17th Street
3067 ft · 58 sec · West 17th Street
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14
Turn right onto South Boulevard
1.6 km · 3 min · South Boulevard
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15
Continue on Stonebrook Lane
142 m · 15 sec · Stonebrook Lane
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16
Turn right onto West Stone Run Lane
74 m · 16 sec · West Stone Run Lane
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17
Turn left onto Charleston Lane
46 m · 7 sec · Charleston Lane
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18
Arrive at your destination
0 m · 1 sec · Charleston Lane
Car Route Details
A richer read on the saved driving route between Post Falls and Idaho 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.
Partly Sunny leaving Post Falls and Mostly Sunny then Slight Chance Light Rain near Idaho Falls.
Trip Questions
Direct answers travelers usually want before committing to the drive.
How long does it take to drive from Post Falls to Idaho Falls?
The road trip is about 490.4 miles (789.3 km) and usually takes 07h 18m 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 243.7 miles from Post Falls and 246.7 miles from Idaho Falls.
How much longer is the road route than the straight-line distance?
The direct path is about 377.7 miles (607.9 km), while the road route adds roughly 112.7 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 $67.39 one way or $134.78 round trip. Estimated CO2 is about 153.8 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 Idaho Falls, so arrival and return times should be read in local time.
What should you check before leaving?
Before you leave, expect Partly Sunny around Post Falls and Mostly Sunny then Slight Chance Light Rain near Idaho Falls.
Flight Path Map
This map shows the direct air route between Post Falls and Idaho Falls. Straight-line distance: 377.74 mi (607.91 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 Idaho Falls
The most populous city in Bonneville County, Idaho.
| Population | 62,888 |
| Coordinates | 43.4665800, -112.0341400 |
| Altitude | 1434 |
| Country | United States |
End: Charleston Lane (-112.034479, 43.46658)
Estimated Travel Time
Distance: 789 km by road
| Speed | Time |
|---|---|
| 30 mph (48.3 km/h) | 16h 20m |
| 40 mph (64.37 km/h) | 12h 15m |
| 50 mph (80.47 km/h) | 09h 48m |
| 60 mph (96.56 km/h) | 08h 10m |
| 70 mph (112.65 km/h) | 07h 00m |
| 80 mph (129 km/h) | 06h 07m |
Fuel, Round Trip and CO2
Estimated fuel cost and emissions for this route.
| Fuel | $/gal | One way | Round trip |
|---|---|---|---|
| Regular gas | $3.89 | $67.39 | $134.78 |
| Mid-grade | $4.23 | $73.24 | $146.48 |
| Premium | $4.55 | $78.74 | $157.49 |
| Diesel | $5.41 | $93.68 | $187.36 |
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 28, 2026
Distance to Other Cities
Planning a road trip? See the full trip guide on Trip.ovh — stops, fuel costs, weather, and departure timing.