The size of your monthly check is arrived at by a series of calculations.
Your primary insurance amount, or PIA -- the benefit you would get at full retirement age -- determines the size of your monthly retirement check. According to the Social Security Administration's website, the PIA is based on the Average Indexed Monthly Earnings, or AIME, as applied to an inflation-adjusted formula. The PIA is then adjusted for whether you take retirement before or after your normal retirement age -- 66 for those now reaching retirement age, but gradually adjusted to age 67 for those born after 1954.
You can begin drawing reduced Social Security as early as 62. For every month you delay after reaching full retirement age, up to age 70, the monthly benefit increases.
According to a recent report of the Senate Special Committee on Aging, for someone with an AIME of $5,000 in 2009, the PIA would total $1,971.
In keeping with the original intent behind Social Security -- a way to lift seniors out of poverty -- lower-wage earners get a higher proportion of their earnings than higher wage earners. The maximum monthly benefit that can be received in 2010 is $2,346.