I'm helping my mother plan senior housing. She has a fixed amount of money in the bank that she can use to pay for housing. Generally housing has an annual increase of, say, 4%.

Using Google sheets, can someone help me to calculate how many years her savings can be used to pay for rent, assuming annual increases, for a range of different rents (e.g. $500-$1000, in $50 increments)?

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    Is her fixed amount of money also earning interest? – Hart CO Jan 28 at 22:24
  • What about food, utilities, etc? – RonJohn Jan 28 at 22:34
  • Try using PV with a graduated adjustment. tvmcalcs.com/index.php/calculators/apps/… This is for Excel, which is very similar to Google Sheets. – Mattman944 Jan 29 at 10:08
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    Why restrain answer to Google sheets? Would an answer that explains how to do the calculations not be sufficient? – yoozer8 Jan 29 at 13:58
  • @RonJohn - If this is assisted living in the US, food and utilities are usually included. Cable TV, probably not; personal items, definitely not. – Mattman944 Jan 29 at 16:16

I said in my comment that you should use PV, after reading your question more carefully, you should use the opposite formula, NPER. The main trick is determining the effective interest rate, which I got from http://www.tvmcalcs.com/index.php/calculators/apps/excel_graduated_annuities

If the money is just in a plain savings account, the savings interest rate is basically zero.

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This is Excel, but Google Sheets also has NPER, I just checked.

Finally, good luck, circumstances change quickly for the elderly. I spent a great deal of time planing out my mother's finances. Less than 6 months later there was a major change, had to start over.

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