Quick answer: A Boulder home valued at the $941,752 median sale price owes about $5,612 in property taxes in 2026, or about 0.60% of value, in the base City of Boulder tax area. That uses the 89.200-mill total on Boulder County's 2025 mill levy list. Other Boulder tax areas run higher.
By Nick Ahrens, Colorado real estate broker license FA.100104470, eXp Realty
Published October 30, 2026.
How much are property taxes on a Boulder home in 2026?
About $5,612 a year on a $941,752 home in the base City of Boulder tax area, which works out to roughly 0.60% of value. That is the 2025 tax bill, paid in 2026, and it comes from Boulder County's own numbers: tax area 0010 carries 89.200 total mills for tax year 2025, per the county's 2025 mill levy changes list. The $941,752 figure is Boulder's median sale price for the three months ending September 2026, per Redfin's Boulder housing market page.
Here is the math on that median home:
School share: $941,752 x 7.05% = $66,394 school assessed value. At 48.044 mills for Boulder Valley School District, that is $3,190.
Local government share: $941,752 x 6.25% = $58,860 local assessed value. At the other 41.156 mills (Boulder County 24.046, City of Boulder 11.648, Boulder Public Library District 3.562, Northern Colorado Water 1.000, Urban Drainage and Flood Control 0.900), that is $2,422.
Total: $5,612 a year, or about $468 a month in a mortgage escrow account.
Those levies add up exactly to 89.200 on the county list, and the two assessment rates come straight from the Boulder County Assessor's tax calculation page.
Nick Ahrens, a North Denver relocation specialist with eXp Realty, tells Boulder buyers to price the tax bill by tax area, not by city name, because two homes inside Boulder city limits can carry very different mill levies.
Sources and as-of dates: Boulder County Assessor 2025 mill levy changes list (tax year 2025, payable 2026) and tax calculation page; Boulder County Treasurer due dates page; Colorado Division of Property Taxation; Colorado Real Estate Commission Contract to Buy and Sell (CBS1, mandatory January 1, 2026); Redfin Boulder data for the three months ending September 2026. All checked October 30, 2026.
What this guide does not cover: commercial or vacant land taxes, property tax exemptions, valuation appeals, special assessments from an HOA, or tax advice. Talk to a CPA or tax advisor about your own situation, and confirm any exact bill with the Boulder County Treasurer.
How is a Boulder property tax bill calculated?
A Boulder bill is two separate calculations added together: actual value times 7.05% times the school mills, plus actual value times the local assessment rate times every other mill. Colorado split residential property into two assessment rates starting with tax year 2025, per the Colorado Division of Property Taxation. The steps:
Actual value: the assessor's market value for your home, set from comparable sales. For tax years 2025 and 2026, those comparable sales had to close between January 1, 2023 and June 30, 2024.
Assessed value: actual value times the assessment rate. For tax year 2025, that is 7.05% for schools and 6.25% for local governments.
Mill levy: each taxing district sets its own. One mill is $1 of tax for every $1,000 of assessed value.
Tax due: school assessed value times school mills, plus local assessed value times local mills.
One point surprises a lot of buyers: your purchase price does not set your current tax value. The assessor's actual value comes from that 2023 to 2024 sales window, and Colorado revalues real property every odd-numbered year, so the next reappraisal is tax year 2027. If you are moving from a state where a sale resets the tax base, read our California vs. Colorado property tax comparison before you budget.
Why does the tax area matter so much in Boulder?
Because Boulder County's 2025 list shows 18 tax areas that include the City of Boulder, and their totals run from 88.200 to 109.770 mills. On a $941,752 home, that spread is worth more than $1,200 a year. Most of these areas carry the same 48.044 Boulder Valley School District levy, so the difference sits in the local share:
Tax area 0010, base City of Boulder: 89.200 mills, about $5,612 a year.
Tax area 0014, adds the University Hills General Improvement District: 90.672 mills, about $5,699.
Tax area 0012, adds the Boulder Central General Improvement District: 92.874 mills, about $5,828.
Tax area 0020, adds the Boulder Rural Fire District: 104.947 mills, about $6,539.
Tax area 0021, adds the Knollwood Metropolitan District: 109.770 mills, about $6,823.
Just outside the city, tax area 0253 (Northern Colorado Water, Urban Drainage and Flood Control, Boulder Rural Fire and the library district, with no city levy) totals 93.299 mills, or about $5,854 on the same value. That is why an unincorporated address is not automatically cheaper.
To find the tax area for a specific address, look it up on the Assessment tab of Boulder County Property Search. If you are comparing Boulder with a nearby town, our Erie property tax guide shows how the Boulder County side of Erie stacks up. School taxes are a levy, not a school assignment: to confirm which schools serve an address, use the official BVSD school finder.
Comparing Boulder homes?
I'll pull the tax area and mill levy for every home on your list, so you compare the real monthly payment and not just the price.
Call or text me: 949-230-3625, or search Boulder homes for sale.
What changes for tax year 2026, paid in 2027?
The local assessment rate rises to 6.8% but now applies after a reduction of 10% of the first $700,000 of actual value, so the median Boulder home's estimate barely moves, to about $5,630 if 2025 levies hold. The school rate stays at 7.05% on full value, per the Boulder County tax calculation page. On the $941,752 home in tax area 0010:
School share: unchanged at about $3,190, since the rate and value stay the same.
Local share: ($941,752 minus $70,000) x 6.8% = $59,279 assessed value, times 41.156 mills = about $2,440.
Total estimate: about $5,630, or $17 more than the 2025 bill.
Two caveats keep this an estimate. First, districts set 2026 mill levies in December 2026, after this post, so the real 2027 bill will use new levies. Second, tax year 2026 is the second year of the same reassessment cycle, so most actual values stay where they were unless the home changed. Boulder County's own example puts an $800,000 home at $4,942 for 2025 and $4,919 for 2026 at the same mills.
How are property taxes handled when you buy a Boulder home?
The seller credits you at closing for the current year's taxes up to the closing date, because Colorado property taxes are paid a year in arrears. Your 2026 taxes are not billed until January 2027, so you pay the full bill even though the seller owned the home for part of the year. The Contract to Buy and Sell (CBS1), section 16.1.1, makes you pick the basis for that credit, per the Colorado Real Estate Commission contract form:
Taxes for the calendar year immediately preceding closing: simple and common, based on last year's bill.
Most recent mill levy and most recent assessed or actual valuation: useful when rates or values changed, as they do in 2026.
Other: any basis you and the seller agree on in writing.
Unless the Additional Provisions say otherwise, those prorations are final. Here is the scale on the median home: a November 30 closing covers 334 of 365 days, so $5,612 x 334 / 365 = about $5,136 credited to you.
Two more contract items matter for taxes. Section 8.5 delivers a Tax Certificate listing any special taxing or metropolitan districts by the Record Title Deadline, and you can terminate if it is unsatisfactory. Section 8.4 warns that metro districts can raise mill levies to pay their debt. After closing, the Boulder County Treasurer's due dates for 2026 were March 2 and June 15 for two half payments, or April 30 for one full payment.
Which Boulder tax estimate should you use?
Use the tax area total for the exact address, then run both the 2025 and the 2026 formula; most buyers should budget the higher of the two until the 2027 bill arrives.
Choose the base-area estimate (about 0.60% of value) if:
The Property Search page shows tax area 0010.
You are comparing several homes and want one starting number.
Choose the full tax-area total if:
The address sits in a general improvement district, fire district or metropolitan district.
The Tax Certificate lists any special district at all.
Choose the mill-levy proration basis in your offer if:
The seller's last bill reflects an exemption that ends at the sale.
You want the credit to track 2026 values and rates instead of last year's bill.
Choose to call the Treasurer before you write an offer if:
The last bill looks out of line with the formula above.
The home was built or remodeled recently, which can change its actual value.
"Boulder buyers spend weeks on the list price and five minutes on the tax area. The tax area can swing the bill by more than $1,200 a year on a median home, so it belongs in the offer math." Nick Ahrens, North Denver relocation specialist with eXp Realty.
Taxes are one line of the Boulder budget. Before you write an offer, read whether Boulder is a buyer's or seller's market right now and what wildfire zones mean for Boulder home insurance. Ready to look? Search homes for sale, see what your current home is worth if you need to sell first, or call or text me at 949-230-3625.
Frequently Asked Questions
What is the property tax rate in Boulder, CO?
In the base City of Boulder tax area, the 2025 total is 89.200 mills, which works out to about 0.60% of actual value once Colorado's two assessment rates are applied. Other Boulder tax areas on the county list run up to 109.770 mills.
How much are property taxes on a $1 million home in Boulder?
About $5,959 a year in the base City of Boulder tax area for tax year 2025, paid in 2026: $3,387 in school taxes plus $2,572 in local taxes. Homes in a fire, improvement or metropolitan district pay more.
Does buying a Boulder home reset the property tax value?
No. For tax years 2025 and 2026, the assessor sets actual value from sales between January 1, 2023 and June 30, 2024, not from your purchase price. Colorado revalues real property every odd-numbered year, so the next reappraisal is tax year 2027.
When are Boulder County property taxes due?
Colorado taxes are paid a year in arrears. For 2025 taxes paid in 2026, the Boulder County Treasurer set two half payments on March 2 and June 15, or one full payment on April 30.
About Nick Ahrens
Nick Ahrens is a Colorado real estate broker with eXp Realty, specializing in Anthem, Anthem Highlands, Baseline and the North Denver suburbs. Call or text 949-230-3625, or visit youranthemhome.com.
