Along the same lines, one way to estimate the total cost of the carbon tax would be to average out Ontario's inflation rates for at least a few months in 2017 vs. the inflation rates in Provinces like Manitoba and Quebec (who didn't bring out a new carbon tax) during the same months.

For example, for January Ontario saw 2.3% year-over-year inflation vs. 1.3% in Quebec and 2.1% in Manitoba.  Of course there is a lot of variation and other reasons why inflation might be lower or higher in any given month, hence why averaging out over a longer of period of time can help "smooth things out".

Sill it is not unreasonable to guess that Ontario's Cap 'n Trade added maybe 0.6 percentage points to inflation, averaging inflation here vs. Manitoba and Quebec.  So if your family's after-tax income is $50,000/year the cap'n'trade tax might be costing you about $300/year?

Actually the cap'n'trade tax is expected to be a bit regressive, so with $50,000/year income it probably costs more than $300.