How Calgary property assessment works

Your assessment is an estimate of what your property was worth on one specific day, made by the City, using a model rather than a visit.

The valuation date is not today

For the 2026 assessment roll, the City valued property as at 2025-07-01. That matters more than most people realise. If the market moved after that date, in either direction, your assessment does not know about it. An argument that starts with what your house is worth now is an argument about the wrong day.

Nobody came to look at your house

Residential assessment in Calgary is mass appraisal. The City models thousands of properties at once from the characteristics it has on file: your lot, your building, your community, when it was built. It does not know that your basement is unfinished, that your foundation moved, or that the previous owner never did the kitchen, unless somebody told it.

This is the single most useful thing to understand about appealing. The City is not being unfair on purpose. It is working from a record, and records have errors in them. Your job is to find the error.

The assessment is not the tax bill

Two different numbers set by two different processes months apart. The assessment is what your property is worth. The tax rate is set later, after the provincial budget lands, by a Council bylaw. For 2026 the combined residential rate was 0.0066499, being a municipal rate of 0.0038906 and a provincial education rate of 0.0027593.

So a reduction in your assessment does not change the rate. It changes the number the rate is applied to. Roughly, every $10,000 off your assessment is about $66 off a year's tax at the 2026 rate.

What is public, and what is not

The City publishes the assessment roll as open data: every parcel, its assessed value, its community, its lot size, its year of construction and its property sub-type. That is what our screener reads.

What is not published is building area. There is no square footage of the house in the open data, at parcel level, anywhere. So no public tool, ours included, can compare your building to your neighbour's building. Anyone who tells you they have done that from public data has not.

Sale prices are also not in the open data. Alberta Land Titles can supply a sale price per title for a fee, one title at a time.