How far is Boulder, CO from Silverthorne, CO?

The driving distance from Boulder, CO to Silverthorne, CO is about 78.6 miles (126.5 km), with a travel time of about 01h 45m by car.

  • The straight-line flight distance is about 50.2 miles (80.8 km).
  • For a round trip, plan for roughly 03h 31m of driving time before adding stops, traffic, or weather delays.
  • A comfortable departure window is usually 8:00 AM to 10:00 AM MDT.
Trip Tools

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.

Reverse Route
Quick Snapshot
Road
78.6 mi
01h 45m
Flight
50.19 mi
80.77 km direct

This route works well as a day trip with time at the destination.

Learn Distance

Choose another destination from Boulder.

Flight Distance

Direct air line
50.19 mi
Kilometers
80.77 km
Flight Time
00h 06m

Driving Distance

Road route
78.6 mi
Kilometers
126.49 km
Drive Time
01h 45m

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 45m.

Arrival Snapshot
Arrive in Silverthorne
Sun, Apr 19, 7:11 AM MDT
Return by in Boulder
Sun, Apr 19, 8:57 AM MDT
Useful when you're deciding between a quick errand, a day trip, or a longer stop.
Leave Boulder
2026-04-19T05:25
Arrive Silverthorne
Sun, Apr 19, 7:11 AM MDT
Route Timing
01h 45m
One way by road
Best Departure Window
8:00 AM to 10:00 AM MDT
Aim for a morning departure
Arrive between
9:46 AM to 11:46 AM MDT

A morning start gives you useful time at the destination and keeps the return out of the late evening.

Leave by
2:58 PM MDT
Keeps a same-day return open with about 03h 00m at the destination.
Back in Boulder
9:30 PM MDT
Morning start is best

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.

Mid-route stop
Idaho Springs
CO

City in Clear Creek County, Colorado, United States

From Boulder
39.3 mi
00h 52m
To Silverthorne
39.3 mi
00h 52m

Route Weather Snapshot

Check the forecast at both ends before you head out.

Origin
64°F
Sunday

Sunny

Starts
Sun, Apr 19 6:00 AM MDT
Wind
2 to 6 mph S
Destination
52°F
Sunday

Sunny

Starts
Sun, Apr 19 6:00 AM MDT
Wind
3 to 8 mph SW

Driving Route Map

The map below follows the saved road route between Boulder and Silverthorne.

Turn-by-Turn Driving Directions

Step-by-step road directions between Boulder and Silverthorne.

  1. 1

    Start on the route

    27 m · 7 sec

  2. 2

    Turn right onto 19th Street

    44 m · 14 sec · 19th Street

  3. 3

    Turn left onto Arapahoe Avenue

    3210 ft · 2 min · Arapahoe Avenue

  4. 4

    Turn right onto 28th Street

    1.2 km · 2 min · 28th Street

  5. 5

    Turn straight onto Baseline Road

    865 ft · 18 sec

  6. 6

    Keep slight left to continue on Baseline Road, Broadway South

    116 m · 16 sec

  7. 7

    Continue on 27th Way

    1484 ft · 46 sec · 27th Way

  8. 8

    At the end of the road, turn left onto Broadway

    2.2 mi · 4 min · Broadway

  9. 9

    Continue on South Foothills Highway

    8.3 mi · 12 min · South Foothills Highway

  10. 10

    Continue straight

    7.5 mi · 11 min

  11. 11

    Continue on Dinosaur Diamond Prehistoric Highway

    2.9 mi · 5 min · Dinosaur Diamond Prehistoric Highway

  12. 12

    Turn right

    2993 ft · 54 sec

  13. 13

    Take the exit slight right toward I 70 West: Grand Junction

    1.3 km · 59 sec

  14. 14

    Merge slight left

    53.6 mi · 1 hr 5 min

  15. 15

    Take the exit slight right toward US 6 East, CO 9 North: Silverthorne, Dillon

    1808 ft · 44 sec

  16. 16

    Keep slight right to continue on CO 9 North: Silverthorne

    90 m · 7 sec

  17. 17

    Merge slight left onto Blue River Parkway

    2046 ft · 1 min · Blue River Parkway

  18. 18

    Continue on Blue River Parkway

    39 m · 12 sec · Blue River Parkway

  19. 19

    Arrive at your destination

    0 m · 1 sec · Blue River Parkway

Car Route Details

A richer read on the saved driving route between Boulder and Silverthorne.

OSRM road route
Drive Character

Highway-focused drive

Most of the mileage stays on named highways, so the important moments are ramps, exits, merges, and the final local approach.

Directions
19 steps
6 turns on the saved route
Ramps & Exits
4
2 merges, 2 ramps or exits
Navigation Density
24.2 / 100 mi
Decision points by distance
Main Roads
I 70 West
54.4 mi · 69%
South Foothills Highway
15.8 mi · 20%
Dinosaur Diamond Prehistoric Highway
2.9 mi · 4%
Broadway
2.19 mi · 3%
28th Street
0.76 mi · 1%
Arapahoe Avenue
0.61 mi · 1%
Longest Stretch

I 70 West

Merge slight left

53.6 mi · 01h 05m

Route Summary

A quick read on whether this route feels easy, ambitious, or worth planning around.

Trip Read

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.

Drive Time
01h 45m
Day trip friendly
Same-Day Return
03h 32m
Round-trip wheel time
Road vs Air
+28.4 mi
50.2 mi direct line
Halfway Stop
Idaho Springs
00h 52m from Boulder
Leave By
2:58 PM MDT
Morning start is best
Weather Watch

Sunny leaving Boulder and Sunny near Silverthorne.

Trip Questions

Direct answers travelers usually want before committing to the drive.

How long does it take to drive from Boulder to Silverthorne?

The road trip is about 78.6 miles (126.5 km) and usually takes 01h 45m 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?

Idaho Springs is a useful midpoint, sitting about 39.3 miles from Boulder and 39.3 miles from Silverthorne.

How much longer is the road route than the straight-line distance?

The direct path is about 50.2 miles (80.8 km), while the road route adds roughly 28.4 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 MDT. If you want a more comfortable same-day return, try to leave by 2:58 PM MDT.

How much will gas cost for this route?

Using about 28.3 MPG, regular gas is estimated at $10.24 one way or $20.49 round trip. Estimated CO2 is about 24.6 kg one way.

What should you check before leaving?

Before you leave, expect Sunny around Boulder and Sunny near Silverthorne.

Stop Ideas Near Idaho Springs

Useful break, food, and waypoint ideas within about 15 miles of the route midpoint.

Mid-route Guidance
Local place coverage is thin around Idaho Springs, so nearby transit and meeting points are shown instead.
Reviewed stop coverage is still thin around this midpoint, so practical transit waypoints are shown on the right.

Transit and Meeting Points

Useful pickup, handoff, or rendezvous points close to Idaho Springs.

BUS

Pine Junction, CO

32 mi away
76 Mount Evans Boulevard
RAIL

Fraser – Winter Park

35 mi away
205 Fraser Avenue
BUS

Boulder, Colorado

40 mi away
30th & Diagonal Highway
RAIL

Union Station

44 mi away
1701 Wynkoop Street

Flight Path Map

This map shows the direct air route between Boulder and Silverthorne. Straight-line distance: 50.19 mi (80.77 km).

Boulder

#1 Boulder

The most populous city in Boulder County, Colorado.

Population107,645
Coordinates40.0149900, -105.2705500
Altitude1624
CountryUnited States
Silverthorne

#2 Silverthorne

Town in Colorado, USA

Population4,906
Coordinates39.6321400, -106.0742800
Altitude2669
CountryUnited States
Start: Boulder (-105.27055, 40.01499)
End: Silverthorne (-106.07428, 39.63214)

Estimated Travel Time

Distance: 126 km by road

SpeedTime
30 mph (48.3 km/h)02h 37m
40 mph (64.37 km/h)01h 57m
50 mph (80.47 km/h)01h 34m
60 mph (96.56 km/h)01h 18m
70 mph (112.65 km/h)01h 07m
80 mph (129 km/h)00h 58m

Fuel, Round Trip and CO2

Estimated fuel cost and emissions for this route.

One-way fuel
2.77 gal
10.5 L · about $10.24
Round trip
$20.49
5.54 gal · 21 L
Estimated CO2
24.6 kg one way
Round trip: 49.2 kg / 108 lb CO2, using regular gasoline.
Fuel$/galOne wayRound trip
Regular gas $3.70 $10.24 $20.49
Mid-grade $4.08 $11.31 $22.63
Premium $4.39 $12.16 $24.33
Diesel $4.74 $13.12 $26.24

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 Colorado · Apr 19, 2026

There is no time difference between Boulder and Silverthorne. The current time is 05:25:38.

Distance to Other Cities

Planning a road trip? See the full trip guide on Trip.ovh — stops, fuel costs, weather, and departure timing.

How did we calculate? Place names are translated into coordinates. The Haversine formula calculates straight-line distance; driving distance uses road network data.