Boulder to Caldwell: Road Trip Guide & Distance

How far is Boulder from Caldwell?

The distance from Boulder to Caldwell is 638.8 miles (1028 km) as the crow flies. Caldwell is located WNW of Boulder. By car, the driving distance is approximately 766.5 miles, taking about 15h 25min. A direct flight would take roughly 1h 47min. Both are located in United States — Boulder in Colorado and Caldwell in Idaho.

This is a serious multi-day road trip! We strongly recommend breaking this journey up with an overnight stay to ensure you arrive safely and refreshed. Since you'll be heading mostly West, pack a good pair of sunglasses if you plan to drive during the late afternoon to avoid the harsh sun glare.

Coordinates come from public place data for Boulder and Caldwell. The driving distance is estimated from straight-line distance with a road-factor model, so confirm the route in your navigation app. Fuel, flight, bus, and train values are planning estimates and can change by date, provider, road closures, and border rules.