There are many factors at play that ultimately affect a person's decision to retire. Physical or mental health can affect a person's decision to retire; if a worker is not physically strong enough, succumbs to a disability, or has mentally declined too much to perform the duties of their job, they should probably consider retiring, or at the very least try to find a new occupation that better accommodates their health. Also, stressors associated with an occupation can become too unbearable, leading to a decline in satisfaction with work. Age is also a factor that affects a person's decision to retire. Theoretically, retirement can happen during any normal working year. Some may choose to "semi-retire" by gradually decreasing their work hours as they approach retirement. Some announce retirement and enter it short-term, just to rejoin the workforce again. However, it generally occurs between the ages of 55 and 70., Another popular rule suggests that an income of 70% to 80% of a worker's pre-retirement income can maintain a retiree's standard of living after retirement. For example, if a person made roughly $100,000 a year on average during his working life, this person can have a similar standard of living with $70,000 - $80,000 a year of income after , This calculator assumes that the year you retire, you do not make any contributions to your retirement savings. So if you retire at age 65, your last contribution occurs when you are actually age 64..