How to calculate lump sum required to generate desired monthly income?

Suppose my monthly expenses are \$500.

I want to ask a charity foundation to finance my scientific research by one-time payment intended to cover all my monthly expenses during my lifetime. How to determine how much to ask?

Note that I live in Israel.

• Please define "long time"? Interest rate also comes into play. What is the interest rate to be used? What problem are you trying to solve? Is this homework? – Chris W. Rea Jun 25 '12 at 12:23
• Long time means "until the existing economical system ends". I am about typical interest rates in the World economy of our time. (In fact, I am interested about interest rates in Israel.) The actual problem is to decide how much money to ask from a charity foundation in order to cover my monthly expenses. It is not a homework. – porton Jun 25 '12 at 12:27
• @Porton: So you want to ask X amount [say 100,000] and every month you keep drawing \$500 till your life time. So if you know you would die in 2 years, ask 500*24, if you know you are going to die in 50 years ask 50*500. Assuming the money earns no interest. If it is supposed to earn interest, do you know what the fixed interest for 50 years would be? Or do you want the intersted to keep generating \$500 and when you die, return the X amount back? And \$500 expense is in today's terms. Do you want to consider inflation? Can you predict what it would be for your lifetime – Dheer Jun 25 '12 at 13:21
• Guys - porton is simply asking, in a roundabout way, for an inflation-adjusted immediate annuity. If a 60 year old asked this as a prelude to retiring, it would make perfect sense. – JTP - Apologise to Monica Jun 25 '12 at 15:19