Estimating your CPP pension has always been something of a dark art. Service Canada has an estimator but it's only an estimator and only works for the common case. If you spent significant amounts of time outside of Canada or have a spotty work history then the estimator will be wrong. So I put together a spreadsheet which will let you compute how much you have earned so far.
This will produce how much pension you would be entitled to if you stopped working and waited until 65 to collect CPP. To fill out the spreadsheet, you will need your statement of contributions from Service Canada or your annual earnings from Revenue Canada. You can estimate your salary for a reasonably close result.
Fill in the Actual Earnings column with your gross pay OR fill in the Pensionable Earning column with your statement of contributions from Service Canada.
Fill in your Data
The final number at the end is the pension you have earned so far in present day dollars. It doesn't impute future earnings and CPP will adjust the amount upwards for inflation.
What do you mean I'll only get a pension of $150!?
That's only the pension you have earned to date. So have a guaranteed pension of $150, your pension will grow as you work more years in Canada.
I'd like to thank Doug Runchey for How to calculate your CPP retirement pension for providing all the math used to calculate the CPP payments.