Time2Retire - the most important pointer I could give you is to take stock of your financial standing right at this point in your career - thus list salary, benefits, special awards, and bonuses (shares or cash), R.A's, Mutual funds, Life Policies, endowments (if you have any), leave accumulated, retrenchment package that the company may offer if retiring at 55, any penalties if you exit your pension fund early etc.
List all these income streams, plus any longer term liabilities that may be in play beyond your retirement horizon age.
I would create a spreadsheet of all your income streams salary and allowances for cast at 3% growth to age of retirement. Then determine from your HR department what portions of your salary package fall away upon retirement and what is your likely pension payout as a percentage of your gross income. If you get anything above 70% as a percentage and that they will give you an annual increase at the CPI rate whilst in retirement, then you will live comfortably. If you have wealth beyond this and you invest judiciously you will survive quite handsomely in your later years which is why you need capital and investments beyond a stable pension program.
I can't see a financial calculator working out whether you can or can't retire at a given age that is totally dependent on present salary what you lose from that gross salary and what your liabilities are currently and how quickly you can liquidate such liabilities. Also as a warning never cash in a portion of your pension to liquidate your liabilities as you will never regain that capital and all future CPI awards will be based on a lower pensionable income. If you have a bond extend its repayment end date - mine is to age 75 and I use it to purchase shares, or to do large property maintenance and repairs, and/or my latest to settle the balloon payment on my car loan.
My advice be creative in using you finances - I turn 70 this year so nobody is going to employ me so I can't generate a new income stream unless I turn my hobby into a business which I have no intention of doing - I retired at 58 and am thoroughly enjoying myself
So best advise do you own sums and underestimate your returns on the income side and overstate the interest rates on the liabilities side of your calculations - some like to call it worst case scenario