Understanding Property Tax Mill Rates in Canada

A mill rate, sometimes called a tax rate, is the amount of property tax charged per $1,000 of assessed property value. The word comes from the Latin millesimum, one thousandth. A mill rate of 10 means $10 of tax for every $1,000 of assessed value, or 1% of assessed value. Some provinces and municipalities publish the figure as a percentage instead, and some publish it per $1,000 while others use per $100,000; OpenStats city pages normalize this so rates can be compared on a common basis.

The mill rate itself is only half the calculation. The other half is the assessed value the rate is applied to, and that assessed value is set by a separate process that varies by province, sometimes substantially from the property's market value.

How the rate is set

Each municipality sets its own mill rate annually as part of its budget process. In simple terms, council decides how much revenue the municipality needs from property tax, divides that figure by the total assessed value of taxable property in the municipality, and the result is the mill rate for the year. When total assessed value rises across a municipality (property values going up broadly), a municipality holding its budget flat will typically lower its mill rate to avoid an automatic revenue windfall purely from valuation growth. This is why a falling mill rate does not necessarily mean falling taxes, and a rising mill rate does not necessarily mean a bigger municipal budget. The two figures, rate and assessed value, have to be read together.

Assessment bases differ by province

Property assessment in Canada is a provincial responsibility, and the methods differ enough that a mill rate from one province is not directly comparable to a mill rate from another without also knowing how assessed value is calculated there.

• Ontario uses the Municipal Property Assessment Corporation (MPAC), which assesses properties on a four-year cycle intended to approximate current value, phased in gradually to smooth large swings.
• British Columbia uses BC Assessment, which reassesses annually based on market value as of July 1 the prior year, so assessed values there tend to track market value more closely and more often than in provinces with longer reassessment cycles.
• Alberta requires municipalities to assess at market value annually, with oversight from the province, and municipalities set their own mill rates within that framework.
• Nova Scotia uses a capped assessment program for most residential properties, which limits how quickly a property's taxable assessment can rise year over year even if market value rises faster, decoupling assessed value from market value over time for long-held properties.

Because of these differences, a municipality with a high mill rate is not automatically a high-tax municipality, and one with a low mill rate is not automatically a low-tax one. A city that assesses close to full market value can post a lower mill rate and still collect a similar or larger dollar amount of tax than a city with an older, capped, or lagging assessment base and a higher mill rate.

Comparing cities without getting misled

The only reliable way to compare the tax burden between two municipalities is to estimate the dollar tax bill on a comparable property value in each place, rather than comparing mill rates directly. That is the approach OpenStats city pages take: each page pairs the current municipal mill rate with an estimated tax bill on a representative home value, and where a calculator is available, it lets a reader plug in their own assessed value to get an estimate specific to their property.

A short comparison checklist

• Check whether each city's assessed values track market value closely or lag behind it.
• Compare estimated dollar tax bills on a similar property value, not raw mill rates.
• Note whether the figure includes education or school board levies, which are set provincially in most of the country and layered on top of the municipal rate.
• Check the assessment year. A mill rate paired with a stale assessed value understates or overstates the real bill.

Municipal levy vs total tax bill

In most provinces, the property tax bill a homeowner receives combines a municipal levy set by council with an education levy set by the province and, in some regions, additional levies for local boards such as conservation authorities or business improvement areas. The municipal mill rate covers only the municipal portion. OpenStats city pages report the municipal residential rate as the primary figure, since that is the number under direct municipal control and the one most useful for comparing local fiscal policy, and note where a combined bill would be materially higher once other levies are added.

Why rates trend the way they do

Municipal tax rates tend to move gradually rather than sharply, because most municipal revenue supports fixed, recurring costs (police, fire, transit, roads, water and sewer infrastructure) that do not change quickly year to year. Sharp year-over-year mill rate changes usually signal either a reassessment year with a large shift in the tax base, a new infrastructure levy or capital project being phased in, or a provincial funding change that shifted cost responsibility onto municipalities. When a city page shows an unusual jump, it is worth checking the municipality's own budget documents for the specific driver rather than assuming a uniform tax increase.

Renters are affected by mill rates indirectly. Property tax is a cost of holding real estate, and landlords factor it into rent-setting decisions over time, though the pass-through is slower and less direct than for an owner-occupier who sees the bill each year.