How far is Boulder, CO from Castle Pines, CO?

The driving distance from Boulder, CO to Castle Pines, CO is about 52.8 miles (85 km), with a travel time of about 01h 08m by car.

  • The straight-line flight distance is about 43.3 miles (69.7 km).
  • For a round trip, plan for roughly 02h 17m 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
52.8 mi
01h 08m
Flight
43.32 mi
69.72 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
43.32 mi
Kilometers
69.72 km
Flight Time
00h 05m

Driving Distance

Road route
52.8 mi
Kilometers
84.98 km
Drive Time
01h 08m

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 08m.

Arrival Snapshot
Arrive in Castle Pines
Wed, Apr 22, 11:42 PM MDT
Return by in Boulder
Thu, Apr 23, 12:51 AM MDT
Useful when you're deciding between a quick errand, a day trip, or a longer stop.
Leave Boulder
2026-04-22T22:33
Arrive Castle Pines
Wed, Apr 22, 11:42 PM MDT
Route Timing
01h 08m
One way by road
Best Departure Window
8:00 AM to 10:00 AM MDT
Aim for a morning departure
Arrive between
9:09 AM to 11:09 AM MDT

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

Leave by
4:12 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
Denver
CO

The twentieth most populous city in the United States and the center of the Denver metropolitan area.

From Boulder
26.4 mi
00h 34m
To Castle Pines
26.4 mi
00h 34m

Route Weather Snapshot

Check the forecast at both ends before you head out.

Origin
75°F
Wednesday

Mostly Sunny

Starts
Wed, Apr 22 6:00 AM MDT
Wind
7 to 17 mph SW
Destination
79°F
Wednesday

Sunny

Starts
Wed, Apr 22 6:00 AM MDT
Wind
9 to 28 mph SW

Driving Route Map

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

Turn-by-Turn Driving Directions

Step-by-step road directions between Boulder and Castle Pines.

  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 Denver–Boulder Turnpike

    3.4 mi · 4 min · Denver–Boulder Turnpike

  6. 6

    Keep slight right to continue on Denver–Boulder Turnpike

    1.7 mi · 2 min · Denver–Boulder Turnpike

  7. 7

    Keep slight right to continue on Denver–Boulder Turnpike

    2.6 mi · 3 min · Denver–Boulder Turnpike

  8. 8

    Keep slight right to continue on Denver–Boulder Turnpike

    2.4 mi · 3 min · Denver–Boulder Turnpike

  9. 9

    Keep slight right to continue on Denver–Boulder Turnpike

    2.2 mi · 3 min · Denver–Boulder Turnpike

  10. 10

    Keep slight right to continue on Denver–Boulder Turnpike

    1.9 mi · 2 min · Denver–Boulder Turnpike

  11. 11

    Keep slight right to continue on Denver–Boulder Turnpike

    2.5 mi · 3 min · Denver–Boulder Turnpike

  12. 12

    Keep slight right to continue on Denver–Boulder Turnpike

    2 mi · 2 min · Denver–Boulder Turnpike

  13. 13

    Keep slight right to continue on Denver–Boulder Turnpike

    1.1 mi · 1 min · Denver–Boulder Turnpike

  14. 14

    Take the exit slight right toward I 25 south: Denver

    2497 ft · 47 sec

  15. 15

    Continue on I 25 south: Denver

    2037 ft · 34 sec

  16. 16

    Merge slight left onto North Valley Highway

    29 mi · 35 min · North Valley Highway

  17. 17

    Take the exit slight right toward Happy Canyon Road

    1582 ft · 41 sec

  18. 18

    Turn right onto East Happy Canyon Road

    134 m · 9 sec · East Happy Canyon Road

  19. 19

    Enter the roundabout and take exit 1 toward Lagae Road

    4 m · 1 sec · Lagae Road

  20. 20

    Exit the roundabout onto Lagae Road

    1834 ft · 57 sec · Lagae Road

  21. 21

    Turn left onto Chase Lane

    1.2 km · 3 min · Chase Lane

  22. 22

    Continue on Lagae Road

    1173 ft · 52 sec · Lagae Road

  23. 23

    At the end of the road, turn right onto Country Club Drive

    762 ft · 34 sec · Country Club Drive

  24. 24

    Arrive at your destination

    0 m · 1 sec · Country Club Parkway

Car Route Details

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

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
24 steps
17 turns on the saved route
Ramps & Exits
5
1 merges, 4 ramps or exits
Navigation Density
45.5 / 100 mi
Decision points by distance
Main Roads
North Valley Highway
29 mi · 55%
Denver–Boulder Turnpike
19.7 mi · 37%
I 25 south
0.86 mi · 2%
28th Street
0.76 mi · 1%
Chase Lane
0.72 mi · 1%
Arapahoe Avenue
0.61 mi · 1%
Longest Stretch

North Valley Highway

Merge slight left onto North Valley Highway

29 mi · 00h 35m

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 08m
Day trip friendly
Same-Day Return
02h 18m
Round-trip wheel time
Road vs Air
+9.5 mi
43.3 mi direct line
Halfway Stop
Denver
00h 34m from Boulder
Leave By
4:12 PM MDT
Morning start is best
Weather Watch

Mostly Sunny leaving Boulder and Sunny near Castle Pines.

Trip Questions

Direct answers travelers usually want before committing to the drive.

How long does it take to drive from Boulder to Castle Pines?

The road trip is about 52.8 miles (85 km) and usually takes 01h 08m 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?

Denver is a useful midpoint, sitting about 26.4 miles from Boulder and 26.4 miles from Castle Pines.

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

The direct path is about 43.3 miles (69.7 km), while the road route adds roughly 9.5 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 8:00 AM to 10:00 AM MDT. If you want a more comfortable same-day return, try to leave by 4:12 PM MDT.

How much will gas cost for this route?

Using about 28.3 MPG, regular gas is estimated at $6.88 one way or $13.76 round trip. Estimated CO2 is about 16.5 kg one way.

What should you check before leaving?

Before you leave, expect Mostly Sunny around Boulder and Sunny near Castle Pines.

Stop Ideas Near Denver

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

Mid-route Guidance
These suggestions come from reviewed places and nearby services around Denver and the surrounding midpoint area.
Fairplay Park
Scenic stop 10.3 mi away

Fairplay Park

Aurora , CO
2200 Altura Blvd, Aurora, CO 80011
Rating 4.2/5 125 reviews Tourist attraction,Park
Denver City Council
Meeting point 1.6 mi away

Denver City Council

Denver , CO
1437 Bannock St rm 451, Denver, CO 80202
Rating 3.6/5 92 reviews City government office,County government office
Town Hall Arts Center
Nearby stop 10.1 mi away

Town Hall Arts Center

Littleton , CO
2450 Main St, Littleton, CO 80120
Rating 4.7/5 204 reviews Performing arts theater,Art gallery
Municipal Court Park
Scenic stop 5.3 mi away

Municipal Court Park

Westminster , CO
3025 W 76th Ave, Westminster, CO 80030
Rating 3.8/5 94 reviews Park

Transit and Meeting Points

Useful pickup, handoff, or rendezvous points close to Denver.

BUS

Denver (Bus Station), Colorado

1 mi away
1055 19th Street
RAIL

Union Station

2 mi away
1701 Wynkoop Street
BUS

Boulder, Colorado

44 mi away
30th & Diagonal Highway
BUS

Pine Junction, CO

46 mi away
76 Mount Evans Boulevard

Flight Path Map

This map shows the direct air route between Boulder and Castle Pines. Straight-line distance: 43.32 mi (69.72 km).

Boulder

#1 Boulder

The most populous city in Boulder County, Colorado.

Population107,645
Coordinates40.0149900, -105.2705500
Altitude1624
CountryUnited States
Castle Pines

#2 Castle Pines

City in Douglas County, Colorado, United States of America

Population11,664
Coordinates39.4580400, -104.8960900
Altitude1999
CountryUnited States
Start: Boulder (-105.27055, 40.01499)
End: Castle Pines (-104.89609, 39.45804)

Estimated Travel Time

Distance: 85 km by road

SpeedTime
30 mph (48.3 km/h)01h 45m
40 mph (64.37 km/h)01h 19m
50 mph (80.47 km/h)01h 03m
60 mph (96.56 km/h)00h 52m
70 mph (112.65 km/h)00h 45m
80 mph (129 km/h)00h 39m

Fuel, Round Trip and CO2

Estimated fuel cost and emissions for this route.

One-way fuel
1.86 gal
7.05 L · about $6.88
Round trip
$13.76
3.72 gal · 14.1 L
Estimated CO2
16.5 kg one way
Round trip: 33.1 kg / 73 lb CO2, using regular gasoline.
Fuel$/galOne wayRound trip
Regular gas $3.70 $6.88 $13.76
Mid-grade $4.08 $7.60 $15.19
Premium $4.39 $8.17 $16.33
Diesel $4.74 $8.81 $17.62

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 23, 2026

There is no time difference between Boulder and Castle Pines. The current time is 22:33:56.

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.