When we're laying the groundwork for our retirement plans, many of us spend hours noodling on optimal asset allocations, withdrawal rates, and income-replacement rates.

But another metric tends to receive far less scrutiny even though it's a far bigger determinant of whether we can retire when and how we'd like to: how much of our income we're able to save while we're working.

I recently surveyed Morningstar.com users about their own savings rates. Posting in the Investing During Retirement forum of Morningstar.com's Discuss forums, I asked readers if they had stuck with the old rule of thumb and saved 10% of their salaries, or if they had nudged their own savings rates higher. I also asked them whether in hindsight their savings rate was too high, too low, or just about right?

Responses, not surprisingly, ran the gamut, and many posters noted that they hadn't saved a fixed percentage throughout their pre-retirement years. Rather, many readers said that they saved somewhat half-heartedly in their younger years, then kicked up their savings rate aggressively when they started to get "real" about retirement, often in their 40s and 50s. "I wish I had started saving more aggressively earlier on!"--or some variation of that statement--was a frequently echoed refrain. To read the complete thread or share your own retirement-savings rate, click here.

'I Have Been Making Up for Lost Time'Although some readers advocated for a flat savings rate, many posters noted that their savings rate trended up as they aged, no doubt the result of a confluence of factors, including higher absolute levels of income, which makes it easier to save, and a greater sense of urgency about retirement, which naturally increases as we age.

The savings pattern laid out by Keith999, who expects to embark on a financially secure retirement soon, will ring true for many investors. "In my 20s I spent, in my 30s I spent more, then in my 40s began saving about 6% of salary, early 50s about 12%, and the last 10 years I/we saved 20% of two salaries. The last 10 years probably represent over 50% of the total saved and indeed has put us over the top of what we need."

ColonelDan's savings rate moved up in stairstep fashion: "I managed to save/invest 5%-10% of my early meager military pay; 10%-15% of military pay in the latter half of those 24 years; 20%-25% of my regular civilian salary plus 100% 401(k) catch-up amount, 100% employer's 401(k) match, and 100% of all bonuses."

Cterry notes that increasing one's savings rate as retirement approaches can have the salutary effect of preparing a pre-retiree to live on a lower income during retirement. "The advantage to ramping up savings so much in the nine years before I retired was that I didn't have to worry about 'Some advisors recommend 90%-100% of current income for retirement--do I need that much?' because I already was living on 70% of my gross."

Playing catch-up is the name of the game for many pre-retirees. For FidlStix, running the numbers on in-retirement income needs was a wake-up call. "About eight years ago I did my first estimate of how much income I might need during retirement. That was a shocker. I was 10s of thousands [of dollars] behind where I needed to be at that point. Since then, I have been making up for lost time. I jumped my percentage of salary saved to 22% including a 5% company match. I also started a Roth IRA five years ago, contributing about 10% additional on average. My total saved this year will be about 38% counting the Roth."

'I Was Finally Able to Really Do Some Saving'Family matters also figured heavily into many posters' savings-rate patterns. Not surprisingly, many readers noted that helping to defray college costs for their children had put a strain on their savings, but with college over, they were able to sock much more away. Juris2 wrote, "I've saved a bit more since my kids ended college in 2003 when I started a supplemental retirement account (SRA). I'm currently putting about 25% per year in my retirement account and SRA combined, including employer contribution, as I approach retirement in two years. (Almost all savings accumulated beyond the RA and SRA were wiped out by college costs for my kids.)"

Original post:
How Much Did You Save for Your Retirement?