Public municipal finance tools
Property Tax Revenue Forecaster
Explain the drivers behind a property-tax revenue scenario. This general planning model separates value growth, additions, reductions, millage, and collections; it does not apply a state-specific tax formula.
No account required. Start with an editable sample.
Reviewed · Editorial responsibility: Aurelius Civic
Results
Baseline projected cash revenue in Year 5
$11,557,946.37
- Base-year cash revenue
- $9,702,000.00
- Baseline revenue change from Year 0
- $1,855,946.37
- Baseline final net taxable value
- $1,117,519,591.15
- Baseline final gross levy
- $11,733,955.71
- Baseline final collection rate
- 98.50%
- Alternative final cash revenue
- $10,063,358.59
Interpretation
General planning model. Entered terminology is preserved; assessed value is used as a taxable proxy without an inferred conversion. No state caps, rollback rules, or legal compliance tests are applied. Each scenario uses visible assumptions and is not a prediction. Review the annual data and ordered driver attribution.
Property-tax scenarios and drivers
Selected starting terminology: Taxable value before modeled reductions. 1 mill = USD 1 per USD 1000; decimal rate = millage ÷ 1000. This is a general planning model.
Annual value, levy, collections, and revenue
Separate axes preserve each measure’s units. Baseline: solid line with circles. Alternative: dashed line with squares. Year 0 and every projected point match the tables below.
Baseline assumptions and annual data
Existing-base growth 2% annually; new additions $15,000,000.00 annually; millage change 0.1 mills per year; collection change 0.1 percentage points per year; annual reductions change $100,000.00 per year. Annual reductions are reapplied to each year’s gross value; the prior adjusted net base carries forward.
| Year | Gross value | Reductions | Net taxable value | Millage | Gross levy | Collection rate | Cash revenue |
|---|---|---|---|---|---|---|---|
| Year 0 | $1,000,000,000.00 | $10,000,000.00 | $990,000,000.00 | 10.00 | $9,900,000.00 | 98.00% | $9,702,000.00 |
| Year 1 | $1,024,800,000.00 | $10,100,000.00 | $1,014,700,000.00 | 10.10 | $10,248,470.00 | 98.10% | $10,053,749.07 |
| Year 2 | $1,049,994,000.00 | $10,200,000.00 | $1,039,794,000.00 | 10.20 | $10,605,898.80 | 98.20% | $10,414,992.62 |
| Year 3 | $1,075,589,880.00 | $10,300,000.00 | $1,065,289,880.00 | 10.30 | $10,972,485.76 | 98.30% | $10,785,953.51 |
| Year 4 | $1,101,595,677.60 | $10,400,000.00 | $1,091,195,677.60 | 10.40 | $11,348,435.05 | 98.40% | $11,166,860.09 |
| Year 5 | $1,128,019,591.15 | $10,500,000.00 | $1,117,519,591.15 | 10.50 | $11,733,955.71 | 98.50% | $11,557,946.37 |
Baseline driver attribution: Year 0 to Year 5
The sum of ordered annual bridges reconciles to the final revenue change. Growth, additions, and reductions use the prior rate and collection. Rate effects use the new net base; collection effects use the new base and rate. Interaction effects are assigned to later steps, so another ordering would change the allocations.
- Existing-base growth
- $1,042,471.11
- New additions
- $751,245.00
- Annual reductions
- -$515,963.30
- Rate changes
- $523,284.32
- Collection changes
- $54,909.25
- Total change from base-year cash revenue
- $1,855,946.37
Alternative assumptions and annual data
Existing-base growth 1% annually; new additions $10,000,000.00 annually; millage change 0 mills per year; collection change -0.2 percentage points per year; annual reductions change $200,000.00 per year. Annual reductions are reapplied to each year’s gross value; the prior adjusted net base carries forward.
| Year | Gross value | Reductions | Net taxable value | Millage | Gross levy | Collection rate | Cash revenue |
|---|---|---|---|---|---|---|---|
| Year 0 | $1,000,000,000.00 | $10,000,000.00 | $990,000,000.00 | 10.00 | $9,900,000.00 | 98.00% | $9,702,000.00 |
| Year 1 | $1,009,900,000.00 | $10,200,000.00 | $999,700,000.00 | 10.00 | $9,997,000.00 | 97.80% | $9,777,066.00 |
| Year 2 | $1,019,697,000.00 | $10,400,000.00 | $1,009,297,000.00 | 10.00 | $10,092,970.00 | 97.60% | $9,850,738.72 |
| Year 3 | $1,029,389,970.00 | $10,600,000.00 | $1,018,789,970.00 | 10.00 | $10,187,899.70 | 97.40% | $9,923,014.31 |
| Year 4 | $1,038,977,869.70 | $10,800,000.00 | $1,028,177,869.70 | 10.00 | $10,281,778.70 | 97.20% | $9,993,888.89 |
| Year 5 | $1,048,459,648.40 | $11,000,000.00 | $1,037,459,648.40 | 10.00 | $10,374,596.48 | 97.00% | $10,063,358.59 |
Alternative driver attribution: Year 0 to Year 5
The sum of ordered annual bridges reconciles to the final revenue change. Growth, additions, and reductions use the prior rate and collection. Rate effects use the new net base; collection effects use the new base and rate. Interaction effects are assigned to later steps, so another ordering would change the allocations.
- Existing-base growth
- $492,467.08
- New additions
- $488,000.00
- Annual reductions
- -$517,240.00
- Rate changes
- $0.00
- Collection changes
- -$101,868.49
- Total change from base-year cash revenue
- $361,358.59
Methodology
Terminology and rate conversion
Choose taxable value before modeled reductions or assessed value used as a taxable proxy. Assessed value is used directly; no assessment ratio, equalization factor, market-value conversion, or legal taxable-base definition is inferred. Enter only reductions not already excluded from the starting value to avoid double counting. The selected label stays visible with results.
Rates are entered in mills: 1 mill means USD 1 of levy per USD 1000 of net taxable value. Decimal rate = millage ÷ 1000. Thus 10 mills = 0.01 = 1%, not 10%. All annual changes to millage are additive mills, while collection changes are additive percentage points.
Annual projection formulas
- Year 0 net taxable value = starting entered value − base-year reductions.
- Projected gross value = prior-year adjusted net value × (1 + existing-base growth ÷ 100) + annual additions.
- Annual reductions in Year y = base-year reductions + y × annual reductions change.
- Net taxable value = projected gross value − that year’s reductions.
- Millage in Year y = base-year millage + y × annual millage change.
- Collection in Year y = base-year collection + y × annual percentage-point change.
- Gross levy = net taxable value × millage ÷ 1000.
- Projected cash revenue = gross levy × collection ÷ 100.
Growth and all selected annual changes apply before Year 1. Additions enter after growth and join the adjusted net base for subsequent growth. Reductions are recurring annual deductions from each projected gross base, not a single one-time exemption. The prior adjusted base carries forward: this convention may differ from a local assessment roll. A constant annual reduction therefore reduces the base again each year. Review whether that convention fits the intended scenario.
Baseline changes may be turned off, holding millage, collection, and annual reductions constant. The optional alternative has five independently editable drivers and starts from the same Year 0 value, reductions, millage, and collection. Its changes remain independent of the baseline toggle. Neither scenario is a prediction or confidence interval.
Driver reconciliation
Each annual bridge applies five changes in order: growth, additions, reductions, rate, then collection. Growth, additions, and reductions are valued at the previous year’s rate and collection; rate effects use the new adjusted base and prior collection; collection effects use the new base and rate. These ordered effects sum to that year’s cash-revenue change. Summing annual effects gives the final change from Year 0. Interaction effects belong to the later step in this order; the allocation is not unique or a causal claim. Display rounding can create cent-level differences when adding displayed components.
Worked example
The sample starts with USD 1,000,000,000 entered taxable value, USD 10,000,000 reductions, 10 mills, and 98% collection. Year 0 net value is USD 990,000,000, levy USD 9,900,000, and cash revenue USD 9,702,000.
Baseline existing-base growth is 2%, additions USD 15,000,000 annually, millage change +0.1 per year, collection change +0.1 percentage points, and reductions change +USD 100,000 annually. Year 1 gross value is USD 1,024,800,000; reductions USD 10,100,000; net value USD 1,014,700,000. At 10.1 mills and 98.1% collection, levy is USD 10,248,470 and cash revenue USD 10,053,749.07. The USD 351,749.07 revenue change reconciles to growth USD 194,040 + additions USD 147,000 − reductions USD 98,980 + rate USD 99,440.60 + collection USD 10,248.47.
The five-year alternative uses 1% growth, USD 10,000,000 additions annually, unchanged millage, −0.2 percentage-point collection change, and +USD 200,000 annual reductions change. Year 5 cash revenue is USD 11,557,946.37 for baseline and USD 10,063,358.59 for alternative. All assumptions are editable. Reset and Load sample restore every field and mode.
Bounds and sources
Starting value, initial reductions, and additions range from zero to USD 1 trillion each. Growth ranges from −100% to +100%; horizon is a whole number from 1 to 10. Millage must stay between 0 and 1000, and collection between 0% and 100%, including all projected years. Annual reductions must remain nonnegative and cannot exceed projected gross value. Violations block results with a year-specific explanation; no silent clamping is applied. Blank optional inputs mean zero. Calculations use unrounded values.
GFOA: Financial Forecasting in the Budget Preparation Process supports transparent forecast assumptions. New York State: Property tax bills illustrates rates stated in dollars per thousand of assessed value; it is included for unit context only. No New York or other state rules are implemented.
Limitations
This is a general planning model, not a parcel tax bill calculator or a determination of lawful levy. Taxable value, assessed value, exemptions, abatements, and collection practices differ by state and jurisdiction. No statutory tax caps, rollback rates, assessment limits, equalization, reassessment cycles, exemption rules, or levy constraints are applied. Confirm definitions and permissible rates with local finance and assessment officials.
The model assumes constant annual additions and growth and additive rate, collection, and reduction changes. It omits delinquency timing, prior-year collections, refunds, appeals, tax-increment arrangements, classification ratios, and multiple taxing districts. Value reductions and cash abatements are different: enter reductions to the value base here, not cash deductions from a levy. The recurring reduction convention and assessed-value proxy may not fit local accounting or law. Future cash revenue remains conditional on the entered assumptions.