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Mortgage Calculator Colorado
Colorado has rewritten its property tax rules three times in five years — a repealed constitutional amendment, a failed ballot measure, and two rounds of legislative fixes. This calculator uses the rate that's actually in effect for 2026.
Estimate your Colorado mortgage payment
Updates liveIllustrative estimate only. Colorado's assessment rate has changed repeatedly since 2020 — see below for the current 2026 rate. Not a loan offer or financial advice.
Diagram: three major shifts in five years explain why Colorado's current assessment rate looks nothing like it did before 2020.
Who checks this calculator
Understanding the Colorado mortgage market
What makes a Colorado mortgage different
Colorado's effective property tax rate is truly among the lowest in the country — but the path to today's rate has been anything but simple, and this mortgage calculator Colorado buyers use reflects where things actually stand before you assume it's fixed for good.
Why Colorado property tax is so low
Colorado's statewide average effective property tax rate runs somewhere around 0.39% to 0.50% of home value — among the very lowest of any US state. The reason is the same mechanism several other low-tax states use: residential property is assessed on only a small fraction of its actual value (roughly 6.8% to 7.05% depending on the taxing entity for 2026), with local mill rates then applied to that much smaller assessed figure rather than the full market price. This mortgage calculator Colorado tool bakes that structure in from the start.
The Gallagher Amendment repeal
Until 2020, Colorado's residential assessment rate was governed by the Gallagher Amendment, a 1982 constitutional provision that automatically adjusted the rate each reassessment cycle to keep residential property's overall share of statewide property tax revenue fixed relative to commercial and other property. As home values rose faster than commercial values statewide, this mechanism repeatedly pushed the residential assessment rate lower over the decades. Voters repealed Gallagher in 2020, removing this automatic adjustment and leaving the legislature to set rates directly through ordinary legislation going forward.
| Year / event | What happened |
|---|---|
| 2020 | Voters repeal the Gallagher Amendment, ending automatic rate adjustment |
| 2023 | Proposition HH, a long-term relief framework, rejected by ~59% of voters |
| 2023 special session | SB23B-001 sets a temporary reduced rate and value exemption |
| 2024 | SB24-233 and HB24B-1001 establish the current framework through 2026 |
Proposition HH's failure and what came after
Proposition HH, referred to voters in 2023, proposed a broader 10-year property tax relief framework alongside changes to the state's revenue cap and school funding mechanisms. It was rejected by nearly three-fifths of the electorate. Rather than leaving the issue unresolved, Governor Polis called a special legislative session that same year, producing SB23B-001, which achieved rate reductions similar in spirit to Prop HH's first-year provisions through ordinary statute instead of a constitutional ballot measure. The legislature followed up in 2024 with SB24-233, and later that year with HB24B-1001 in a second special session, establishing the framework currently in effect.
The actual 2026 assessment rates
For the 2026 property tax year, Colorado's residential assessment rate for local government levies is 6.8%, applied after a 10%-of-value reduction capped at $70,000 (adjusted for inflation), while the rate for school district mill levies is 7.05%, per the Colorado Division of Property Taxation. Most non-residential property (commercial and agricultural) is assessed at 25%, and other classifications at 26%, both well below the historical fixed 29% rate that applied before recent reforms.
The senior homestead exemption
Separate from the assessment rate itself, qualifying seniors aged 65 and older, and 100% disabled veterans, can exempt 50% of the first $200,000 of their primary residence's actual value from property tax — a meaningful additional reduction for eligible long-term homeowners, stacking on top of the standard assessment rate mechanics.
The 5.5% local revenue growth cap
As part of the post-Prop-HH legislative package, most non-school local governments now face a cap limiting annual property tax revenue growth to 5.5%, with a comparable but distinct cap applying to school district revenue. Because Colorado's assessment cycles run in two-year periods and this cap is also measured over two years, there's some flexibility built in — a local government could retain revenue growth of up to roughly 10.5% over a full cycle, and schools up to about 12%, without triggering additional restrictions.
A worked example, start to finish. Say a buyer purchases a $550,000 home in Colorado, in a district with an effective tax rate of about 0.47% once the 2026 assessment rate and local mill levy are combined. With a 10% down payment, they're financing $495,000 at 6.6% over 30 years, giving a principal and interest payment of roughly $3,157.
Property tax adds about $215 a month — quite modest compared to what a $550,000 home would cost in property tax in most other states. Add typical Colorado insurance, and the full monthly payment comes to about $3,332.
If this same buyer qualifies for the senior homestead exemption years later, exempting 50% of the first $200,000 of their home's actual value would meaningfully reduce their taxable base further, on top of the already-low assessment rate — a real, significant combined benefit for eligible long-term Colorado homeowners.
How to use this mortgage calculator Colorado tool
Enter the home price and down payment you're working with, along with your expected interest rate and loan term. The effective tax rate field defaults to a typical statewide figure of 0.47%, already reflecting the 2026 assessment rate structure — adjust it if you know your specific county and district's actual combined rate. Add an estimated annual insurance premium, and this mortgage calculator Colorado shows your full estimated monthly payment.
Common mistakes to avoid
- Using an outdated pre-2023 assessment rate. Colorado's rate has really changed several times since then — confirm the current figure.
- Applying the local mill rate to full market value. Only the small assessed value (roughly 6.8-7.05% of actual value) is what's taxed.
- Not checking senior exemption eligibility. It's a meaningful additional reduction, stacking on top of the low assessment rate.
- Assuming the current rates are permanent. Colorado's legislature has adjusted this framework multiple times recently and may again.
- Forgetting the residential and school district rates differ. Local government (6.8%) and school district (7.05%) levies use different assessment rates.
Quick glossary
- Gallagher Amendment
- A repealed 1982 Colorado constitutional provision that automatically adjusted the residential assessment rate to hold residential property's revenue share fixed.
- Proposition HH
- A 2023 ballot measure proposing broader property tax relief, rejected by voters, that prompted subsequent legislative reform instead.
- Assessment rate
- The percentage of actual value used to calculate a property's taxable assessed value in Colorado, set directly by the legislature since Gallagher's repeal.
- Senior homestead exemption
- A Colorado benefit exempting 50% of the first $200,000 of actual value from tax for qualifying seniors and 100% disabled veterans.
- Revenue growth cap
- A limit on how much most local governments' total property tax revenue can grow annually, currently 5.5% for non-school entities.
The bottom line
Colorado's property tax is truly among the lowest in the country, the product of a small assessment rate applied to actual value rather than a low mill rate alone — but that rate has been legislatively adjusted repeatedly in the past few years, and further change remains a real possibility. Confirm the current rate with your county assessor, check senior exemption eligibility if it applies, and this mortgage calculator Colorado gives you a realistic, up-to-date starting point for what a home here actually costs each month.
Common questions