Gas Prices in Boulder, CO Today

Boulder drivers are paying around $3.45 to $3.75 per gallon in May 2026, tracking close to the broader Denver-Front Range average. Boulder benefits from Colorado's relatively low state gas tax and short proximity to the Suncor refinery north of Denver, the only large refinery still operating in the state. The result is a fuel market that prices much more reasonably than mountain destinations like Aspen 100 miles to the west.

Why Boulder Tracks Front Range Pricing

Colorado charges 22 cents per gallon in state gas tax, among the lowest in the country. Boulder County adds modest local option fuel taxes. The bigger driver of Boulder retail pricing is its proximity to the Suncor Commerce City refinery (about 30 miles southeast) and the broader Front Range distribution network. That short overland delivery distance keeps logistics costs low and supply consistent.

Boulder also has high retail competition density along Pearl Street, the 28th Street and 30th Street corridors, and the Highway 36 / Foothills Parkway entries. Murphy USA, King Soopers Fuel, Sam's Club, and Costco all maintain Front Range presence that influences Boulder pricing. The result is a competitive everyday market with relatively narrow spreads between cheapest and most expensive stations within the same ZIP.

Where to Find Cheaper Gas in Boulder

The Boulder metro covers downtown, the CU campus area, the 28th Street commercial corridor, and the surrounding suburbs.

• East Boulder / 28th Street corridor, 80301, 80303, the most competitive everyday pricing
• North Boulder / 30th Street, 80304, reliable mid-range
• Downtown Boulder / Pearl Street area, 80302, tourist-corridor pricing slightly elevated
• South Boulder / Table Mesa, 80305, suburban pricing with high-volume stations
• Gunbarrel / Niwot side, 80301, competitive corridor for east-side commuters
• Costco Superior (10 miles south), the cheapest reliable fill within range, often 25 to 35 cents below Boulder retail

Practical Tips for Boulder Drivers

The Costco Superior is the single biggest savings move for households fueling weekly. The 10-minute drive saves 25 to 35 cents per gallon, paying back the annual membership within 2 to 3 months at typical fill rates. The Sam's Club in Lafayette is similarly competitive and worth the trip from east Boulder.

For everyday fills in town, the East Boulder corridor (28th Street, Foothills, and 30th Street) consistently runs cheaper than downtown or the Pearl Street side. King Soopers Fuel offers loyalty-program savings that stack visible discounts for grocery shoppers, typically 10 to 30 cents off per gallon depending on accumulated spend.

For mountain-driving residents, monthly tire pressure checks matter. Cold mornings drop tire pressure 1 PSI per 10 degree drop, and underinflation costs 1 to 3 percent of MPG. A fuel system cleaner every 3 to 4 months also helps maintain efficiency on older vehicles at altitude.

Outlook and Mountain Trip Pricing

Boulder pricing tracks Denver closely year-round. The mountain-resort premium kicks in only when you head west into the Front Range corridors: Estes Park (gateway to Rocky Mountain National Park), Idaho Springs, Frisco, and points west all run 30 to 70 cents above Boulder. For tourists heading into Rocky Mountain National Park or to ski country, filling up in Boulder or the I-25 corridor before heading west is materially cheaper than mountain-town pumping.

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