I've been trying to run numbers to get an idea of where I am and how much I need to retire. I've rounded the example numbers below.
Say I need $30,000 a year to maintain my current lifestyle.
To support that indefinitely with a 4% withdrawal rate requires $750,000 in investments. So, I would need $750,000 plus the balance remaining on my mortgage. But, in theory, I wouldn't need to rely on that alone. After a certain age, I will start getting pension and social security payments.
With pension and social security, I will need significantly less than $750,000 and might even need $0 depending on how long it takes me to save up enough. So, I do not need to save $750,000 in order to retire. At my current investment rate, I can save until I hit around $380,000 + the remaining balance on my mortgage.
Then, I withdraw the investments down to the amount required at retirement. Even not counting on social security, and just the pension, I need $435,000 plus the balance of the mortgage. This cuts out a large amount of time working. But, maybe it's too aggressive and depends on things that I can't control.
I feel that my pension is pretty secure, and that I can rely on it being there. The social security is less secure, in my calculations.
The difference is around 10 years. I hope to increase my contributions, regardless, but this is just looking at current numbers.
With only investments: ~ 260 months to retire
With investments + pension: ~ 200 months to retire
With pension + social security: ~ 160 months to retire
The only downside to this would be leaving less for my son after I am gone, because I won't be leaving an amount that provides a full income indefinitely.