For most employees, the common law entitlement will make up the most important aspect of their claim. After taking all of the relevant factors into consideration, an employee's reasonable notice entitlement can be estimated. Unlike the calculation of the entitlement under a statute such as the Employment Standards Act or the Canada Labour Code, there is not a strict arithmetical formula to apply. The determination of a reasonable notice period is not an exact science, and there will be variability in estimating your own entitlement.

The most reliable estimate will come from a lawyer specializing in employment law, who is in a position to keep abreast of the relevant legal principles and legal cases which determine legal entitlement. You cannot rely on your employer for advice on how much notice is reasonable.

Some general rules to keep in mind though are as follows:

• It is extremely unlikely that your notice entitlement will ever be found to exceed 24 months, unless you have a written employment agreement which provides for such an amount. The Ontario Court of Appeal has stated that 24 months is an informal maximum period of notice.
• A higher level executive or professional with a relatively brief period of service is likely to be entitled to at least 6 months.
• An entry level employee is not likely to receive more than a year's notice no matter how long the person has held that position.
• Sometimes an employee has done something which borders on entitling the employer to terminate the employee for just cause, but does not quite cross over that line. In such a case, an employer might still argue that the employee should receive less compensation than the employee against whom there are no complaints. This concept has been nicknamed "near cause". However, the law is that being close to the line does not reduce an employee's entitlement to compensation.
• The most common amounts of notice awarded by judges are 3, 4, 6, 8, 9, 12, 15 and 18 months.
• Highly unlikely amounts of notice are 11, 13, 17 and 19 months.