Missouri Property Tax Assessment Calculator

How this calculator works

Missouri property tax is governed by Mo. Rev. Stat. Chapter 137 (Assessment and Levy of Property Taxes) and constrained by the Hancock Amendment (Mo. Const. Art. X §§ 16–24, with property-tax implementing rules at § 137.073). Three structural features distinguish Missouri's system from most other states:

• Class-based assessment ratios under § 137.115.5 — four constitutional sub-classes, each with a fixed ratio
• Hancock rollback under § 137.073 — automatic levy reduction when reassessment produces aggregate assessed-value growth above the lesser of 5% or the CPI inflation rate
• Senior Property Tax Credit under § 135.010 through § 135.035 — refundable income-tax credit (the "Circuit Breaker") of up to $1,100 for owners or $750 for renters

The math:

• true market value × class ratio = assessed value (§ 137.115)
• assessed value × combined levy ÷ 100 = gross tax (levies quoted per $100 of assessed value)
• gross tax − Circuit Breaker credit = net tax (§ 135.025)

Everything else is determining the right class ratio, the right combined levy, and Circuit Breaker eligibility.

The class-based assessment ratios — § 137.115.5

Mo. Const. Art. X § 4(b) and § 137.115.5 set four constitutional sub-classes of taxable property. Each carries a fixed ratio that has not changed since adoption:

| Sub-class | Ratio | Applied to | | --- | --- | --- | | Residential (Subclass 1) | 19% | true market value | | Agricultural (Subclass 2) | 12% | productive value (§ 137.021) | | Commercial (Subclass 3) | 32% | true market value | | Personal property | 33⅓% | true market value |

The assessor first determines true market value (or productive value for agricultural land) and then applies the class ratio to produce the assessed value that the tax rate runs against.

The split is a deliberate policy choice. Residential owners get the lowest ratio. Commercial bears the largest share. Agricultural land is taxed on its earning capacity rather than its market value as developable land — the productive-value figures are set by the State Tax Commission across eight soil-productivity grades under § 137.021, and they are typically a small fraction of the parcel's market value as developable land.

A multi-use parcel may be split-assessed (residence + barn + acreage) with each component carrying its own class ratio. Changing a ratio requires a constitutional amendment, not a statutory change.

The Hancock Amendment and the § 137.073 rollback

The Hancock Amendment (Mo. Const. Art. X §§ 16–24, adopted in 1980) caps state and local government revenue growth at the rate of personal-income growth. The property-tax-specific implementation in § 137.073 says:

When a county-wide reassessment produces aggregate assessed-value growth above the lesser of 5% or the CPI inflation rate, each affected taxing jurisdiction MUST roll back its tax rate to the level that would have produced the same revenue as the prior year, plus the CPI increment.

The mechanism prevents local government from collecting a reassessment windfall. Voters can approve overrides by referendum, but the default rule is automatic rollback. In practice the rollback typically reduces published levies by 1%–4% in odd-numbered (reassessment) years.

A worked rollback example. St. Louis County's 2023 reassessment produced aggregate residential assessed-value growth of about 14%. CPI for the period was about 3.2%. The Hancock ceiling is min(5%, 3.2%) = 3.2%, well below the 14% growth — so the rollback triggered. The rollover factor was approximately 1.032 / 1.14 ≈ 0.905, meaning local levies had to roll back by about 9.5% in 2023 to comply with § 137.073. Most St. Louis County taxing jurisdictions ran rollback notices in the August 2023 county newspapers as required.

The calculator exports computeHancockRollback as a standalone helper that can be called against any aggregate-assessed-value pair plus a CPI figure to estimate the required rollover factor.

Levies are quoted per $100 of assessed value

Missouri property-tax bills follow the historical convention of quoting dollars per $100 of assessed value — the same convention used in Tennessee, North Carolina, and Kentucky. A combined levy of $7.50 per $100 means $7.50 of tax per $100 of assessed value — equivalent to 7.5% of assessed value.

At Missouri's 19% residential class ratio, that works out to 7.5% × 19% = 1.425% of market value.

This double-conversion (assessed value at 19% of market, levy at 7.5% of assessed) is the most common error in Missouri property-tax estimation. The county collector's bill quotes the assessed value and the levy; the bill is correct but the effective rate on market value is not the levy itself — it's the levy times the class ratio.

Typical combined levies by county

Combined levies (county + school + city + library + fire) for 2024–2025 on residential primary residences, in dollars per $100 of assessed value, with the corresponding effective rate on market value at the 19% residential ratio:

| County | Combined levy ($/$100) | Effective rate (market) | $300K home gross tax | | --- | --- | --- | --- | | Franklin | $5.70 | 1.08% | $3,249 | | Greene (Springfield) | $5.90 | 1.12% | $3,363 | | Jefferson | $6.10 | 1.16% | $3,477 | | Boone (Columbia) | $6.30 | 1.20% | $3,591 | | St. Charles | $6.40 | 1.22% | $3,648 | | Clay | $7.20 | 1.37% | $4,104 | | Jackson (Kansas City) | $7.80 | 1.48% | $4,446 | | St. Louis County | $8.20 | 1.56% | $4,674 | | Rural / other (typical) | $5.50 | 1.05% | $3,135 |

Pull the binding combined levy from the county collector's annual tax bill or the State Auditor's tax-rate database. Municipal and special-district add-ons vary block-by-block — most parcels diverge from the county average.

The Senior Property Tax Credit — § 135.010 through § 135.035

The Circuit Breaker is a refundable Missouri income-tax credit on Form MO-PTC, not a property-tax exemption. The county collector still bills the gross figure; the claimant recovers a portion through the income-tax filing.

Eligibility (§ 135.010(3)). The claimant must be one of:

• Age 65 or older
• 100% disabled (SSA, VA, or physician certification)
• A surviving spouse age 60 or older of a person who would have qualified

Maximum credit (§ 135.025).

• Owners: up to $1,100 against actual property tax paid
• Renters: up to $750, computed against 20% of gross rent paid (deemed property tax under § 135.025.2)

Income limits (§ 135.030).

| Status | Income limit | | --- | --- | | Single owner | $30,000 | | Married filing joint owner | $34,000 | | Single renter | $27,500 | | Married filing joint renter | $29,500 |

The credit phases down as income approaches the limit. The published Form MO-PTC schedule effectively reduces the credit by about 4%–7% on each additional $1,000 of income above the base income floor (~$14,300). At the income limit the credit reaches roughly zero. File MO-PTC by April 15 alongside the Missouri income-tax return (Form MO-1040), or by itself if no income-tax return is required.

A worked example — $300,000 St. Louis County home, owner age 45

A $300,000 home in St. Louis County. Owner is 45, not disabled, household income $90,000. St. Louis County's typical combined levy is $8.20 per $100 of assessed value.

• Market value: $300,000
• Assessed value (residential, 19%): $300,000 × 0.19 = $57,000
• Gross tax: $57,000 × 8.20 ÷ 100 = $4,674
• Circuit Breaker: not applicable (under 65, not disabled, income above limit)
• Net tax: $4,674
• Effective rate: $4,674 ÷ $300,000 = 1.558% of market value

This is the working-age non-veteran baseline. No exclusions apply; the tax is assessed value times levy.

A worked example — same home, age 70, income $14,300

Same $300,000 St. Louis County home. Owner is now 70, household income $14,300 — at the Circuit Breaker base income, well below the $30,000 single-owner limit.

• Assessed value: $57,000
• Gross tax: $4,674
• Circuit Breaker credit: capped at the $1,100 owner maximum (income at base, no phase-down)
• Net tax: $4,674 − $1,100 = $3,574
• Effective rate: 1.19% of market value

The $1,100 credit reduces the effective tax by about 24% on this $300K home. The credit is refundable, so the senior owner receives a check from the Missouri Department of Revenue if the credit exceeds the income tax owed.

A worked example — Jackson County (Kansas City) renter, age 70

A renter age 70 in Kansas City. Annual gross rent $9,000. Household income $18,000 (above the base, below the $27,500 single-renter limit).

• Deemed property tax: 20% × $9,000 = $1,800
• Credit at base income: $750 (max renter cap)
• Income above base: $18,000 − $14,300 = $3,700
• Phase-down: at roughly $750 ÷ ($27,500 − $14,300) = $0.057 per dollar above base, $3,700 × $0.057 ≈ $210 reduction
• Phased credit: $750 − $210 = about $540
• Net rent-equivalent tax: $1,800 − $540 = $1,260 for the year

Renters claim the credit on Form MO-CRP (rent receipt) attached to MO-PTC. The landlord's signature on MO-CRP is required.

A worked example — agricultural land at productive value

A 40-acre Boone County parcel. True market value as developable land: $400,000 ($10,000/acre). The assessor's productive value under § 137.021: $40,000 ($1,000/acre, reflecting Grade 3 cropland). Combined levy $6.30/$100.

• Productive value (the assessor's binding figure): $40,000
• Assessed value (agricultural, 12%): $40,000 × 0.12 = $4,800
• Gross tax: $4,800 × 6.30 ÷ 100 = $302
• Compare to residential at market: $400,000 × 0.19 × 6.30 ÷ 100 = $4,788
• Annual savings from agricultural classification: $4,486

Agricultural classification is the largest property-tax benefit available on Missouri parcels of any size. The catch: removal from the agricultural classification (e.g., a developer purchases the land for subdivision) triggers retroactive rollback at the higher residential or commercial rate. The seller pays the difference on the prior years' assessments.

A worked example — commercial property in Springfield

A $1,000,000 commercial parcel in Springfield (Greene County). Owner is a corporate entity. Combined levy $5.90/$100.

• Market value: $1,000,000
• Assessed value (commercial, 32%): $1,000,000 × 0.32 = $320,000
• Gross tax: $320,000 × 5.90 ÷ 100 = $18,880
• Effective rate: 1.89% of market value
• Compare to residential at the same value and levy: $1,000,000 × 0.19 × 5.90 ÷ 100 = $11,210 — commercial pays 68% more

Commercial owners can challenge the assessor's valuation through the State Tax Commission and the courts, but cannot challenge the 32% class ratio — it is constitutionally locked.

St. Louis County vs Jackson County — practical differences

Both counties run on the same statutory framework. The differences are administrative.

St. Louis County has the higher published levy (~$8.20/$100 combined) but tighter assessor practices. Reassessments tend to track market values closely. The State Tax Commission appeals process is heavily used, and Hancock rollbacks are routinely applied. The bill arrives in late October with payment due by December 31. Refunds for over-collection are processed through the county collector's office within 60 days of the appeals decision.

Jackson County (Kansas City) has a lower published levy (~$7.80/$100) but a history of contentious reassessments. The 2023 county-wide reassessment produced a class-action lawsuit, a state audit, and ongoing litigation through 2024–2025 over the assessor's mass-appraisal methodology. The county was found to have violated several due-process protections — failure to send notice to a substantial number of owners, inadequate hearing procedures, and inconsistent application of the comparable-sales method. The State Tax Commission ordered a partial rollback of the 2023 increases pending resolution.

For owners in Jackson County, the practical takeaway: expect to appeal more often than St. Louis County peers, and monitor the assessor's litigation status before assuming the published assessed value is binding for the year. The State Auditor publishes annual reviews of each county's assessment practices; consult that report before signing off on the bill.

Comparing Missouri to surrounding states

Effective property-tax rates on residential primary residences across the central US:

| State | Effective rate (typical) | Why | | --- | --- | --- | | Tennessee | ~0.65% | 25% residential ratio | | Kentucky | ~0.85% | 100% ratio, low combined rates | | Arkansas | ~0.65% | 20% residential ratio + homestead credit | | Missouri | ~1.0%–1.6% | 19% ratio, varies sharply by county levy | | Kansas | ~1.40% | 11.5% residential ratio but very high levies | | Iowa | ~1.50% | 56% residential rollback, high levies | | Illinois | ~2.0%–2.5% | Cook County multiplier + high local levies |

Missouri sits in the middle — well below Illinois, Iowa, and Texas (1.6%–2.0%), modestly above Tennessee and Arkansas, broadly comparable to Kentucky and Virginia. The mid-tier ranking reflects the trade-off: low statutory class ratios for residential (19%) keep effective rates from spiking, but the combined levies in the major metros (Jackson and St. Louis) drag the effective rate up to ~1.5% — comparable to Iowa or Kansas City's Kansas-side suburbs.

Common errors to avoid

• Multiplying the levy by market value instead of assessed value. The levy is in dollars per $100 of ASSESSED value, not market value. A $7.50/$100 levy on a $300,000 home is NOT $22,500 of tax — it is ($300,000 × 0.19) × $7.50 ÷ $100 = $4,275.
• Forgetting the class ratio. Commercial pays 32% × levy. Residential pays 19% × levy. The same parcel switched from residential to commercial nearly doubles the tax. Mixed-use parcels are split-assessed and each component carries its own ratio.
• Confusing the Senior Property Tax Credit with a tax exemption. The credit is a refundable INCOME-tax credit, claimed on Form MO-PTC. The county collector still bills the full gross figure; the claimant recovers a portion through the Missouri income-tax return. Failure to file MO-PTC means no credit — the credit does NOT apply automatically.
• Missing the agricultural rollback at sale. Selling agricultural land to a non-agricultural buyer triggers retroactive reassessment at the residential or commercial rate plus a rollback of the prior years' tax savings. Negotiate the rollback liability in the sale contract.
• Assuming the assessor's value is binding. Missouri allows appeals to the county Board of Equalization (June–July) and then to the State Tax Commission (typically a 90-day window after the BOE decision). Contested values can be lowered if the comparable-sales evidence supports a lower figure.
• Ignoring Hancock rollback notices. In reassessment years (odd-numbered), check the county newspaper for the August Hancock rollback notice. The published levy may be lower than the prior year even though assessed values went up. Failing to apply the rolled-back levy is one of the more common mistakes in DIY property-tax estimation.
• Missing the April 15 MO-PTC deadline. Late filings within three years may be accepted under § 143.801; older claims are time-barred. File even if eligibility is uncertain — the Department of Revenue determines qualification on the form.

Tools, not advice. Confirm the binding class ratio, productive value (agricultural), combined levy rate, and Circuit Breaker eligibility with the county assessor and the Missouri Department of Revenue before relying on any result for planning purposes.

Last reviewed against Mo. Rev. Stat. §§ 137.073, 137.100, 137.115, 135.010 through 135.035, and Mo. Const. Art. X § 22 on 2026-05-16.