It varies widely between small employers, large corporations, profitability and generosity of the company, etc. Between 3% - 6% is pretty common .
As William indicated, it can be very different based on company size, profitability, and other factors. Most commonly, companies MATCH 4-6% but I have seen many plans that don't match or contribute and a few that contribute much more, closer to 10% for their employees.
Hi Daniel, typically a company will limit the amount of their contribution into the 401(k) based on the amount you contribute. If you contribute say 3% of your pay the company may match your contribution up to a limit. In this area a typical match is 3 - 6% as the other advisors have stated.
Matching contributions from companies are typically in the range of 3% - 6% of income, usually as a dollar-for-dollar match or a 50-cents-on-the-dollar match.
Companies may also make "profit-sharing" contributions to your account as well. This varies widely by company; many do not make contributions at all, while others make significant (5%? 10%? 20%?) contributions regularly. The maximum by law for profit-sharing plans is generally 25%, though it's uncommon to see businesses do so outside of unusual situations with small business owners contributing mostly for themselves.
Daniel: I agree with the previous comments in terms of the typical matching contribution range. Another important issue to consider with a company match is what form the match takes. Many larger companies will fund their matching contributions with company stock, which helps them conserve cash, but might not be great for you. To be properly diversified, you don't want your account to be overly concentrated in any one investment. If your employer matches with company stock, you should periodically rebalance your portfolio by transferring out of company stock and into a diversified mutual fund.
The others have given good answers to your question. Keep in mind why companies offer 401k plans in the first place. One of the main reasons is to allow the highest paid employees (i.e. the owner in case of a small business) to save - tax deferred - for their own retirement. They are usually the biggest contributors to their 401k plan. The second is to attract better workers and reward them for their loyalty. The third is to retain good employees by offering them an incentive that they may not find at other companies. If you are asking the question because you are an employer thinking about offering a 401k plan you have to balance what you can afford versus what your employees want. If you are an employee, a 401k plan is a nice benefit, especially if the employer matches part of your contribution, but it should not be the biggest reason for taking or keeping a job. There are many other ways to save for retirement.