That's a more complicated question then all of those «online severance calculators» make it seem. (torontoemployment.law)
It's pretty good, definitely useful, clearly superior to simple severance calculators, but still far from perfect. (bardalfactors.ca)
If you use the Ontario Ministry of Labour Severance Calculator the answer will be one week of notice, plus nothing for severance. (ottawaemploymentlaw.com)