What's a good rate of return percentage to fill out a retirement calculator with?

it depends on your age - you should have more aggressive investments when you are young, and more conservative investments when you get closer to retirement.

It also depends on your personal risk tolerance. Do you want a retirement plan that gives you a very high chance of having modest retirement, or a plan that gives you some chance of lucrative retirement with some chance that you'll come up short and have to work longer?

Looking at VERY long term numbers, like returns over 60+ year time periods, here are some very typical values:

4% for a stable investment with virtually no risk. Your money just barely keeps up with inflation.

6% for a conservative investment. The kind of portfolio you might have after retirement where you get a little bit of growth but only small risk of losing money if your investments do poorly

8% - average return for modest risk portfolio where you expect to have some strong years and ride through a few modest downturns.

10% - solid returns on a portfolio that isn't afraid of risk, someone who likes the bigger swings of ups and downs or someone who is young and can afford to risk a big loss in exchange for a shot a huge gain.

12% or higher - high risk, generally the kind of thing you'd do outside of your normal investment because you're hoping something takes off, like buying stocks in start up companies on the hope that they turn into the next apple/google type success story.

Again, these are very generic numbers and can change a lot, and might not be accurate in today's circumstances. 8% is a good solid number, you should be beating that figure in good years but the bad years will pull it down to a long term average around 8% with a *typical* 401k portfolio.

Average return for broad stock market over past 100 years is just under 10%. Presumably you will move some assets into more conservative assets as you age. In addition, it's better to underestimate your returns than overestimate so that you aren't lured into a false sense of security. I use about 7% in my planning numbers (but over the past 30 years I've consistently done better than that).

You didn't say what you're investing in so it's hard to tell you what rate to choose. What I CAN say is that whatever you are investing in has underperformed the S&P Index.

On average you should be making 6-9% per year.

I'd review your investments if you are only making 2%.