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GBIC >> Retirement >> Online Calculators
Online Calculators
Investment is about making decisions - deciding how much money to invest, estimating the return on an investment, comparing various investment options and determining the cash flow an investment can support during retirement. To help answer these questions, this page provides several online calculators, representing some of the most common questions that an investor or retiree might ask.

For more complete retirement financial calculations be sure to check out the Lifetime and Retirement planners at this site.

This page only allows selection of values using dropdown lists. If you need to enter values not available from the dropdown lists on this page, try out the second version of this page that allows manual entry of values (not limited to the dropdown values on this page).

Online Calculators Instructions Equations


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Online Calculators

For each online calculator, select the values using the dropdown lists. Calculation of the results will take place automatically. The result will appear in the right-most text box (to the right of the green arrow).

1. Payment: If I purchase something how much will the monthly payments be?
Price Rate Years
  Monthly Payment

 

2. Investment:

If I invest a lump sum of money today, how much will it be worth in the future?
PV Rate Years
  Future Value

 

3. Investment:

If I save money each month, how much will the investment be worth in the future?
Savings Rate Years
  Future Value

 

4. Investment:

If I need to have a specific amount of money in the future, what lump sum should I invest today?
FV Rate Years
  Present Value

 

5. Investment:

If I need to have a specific amount of money in the future, how much should I invest per month starting today?
FV Rate Years
  Monthly Investment

 

6. Withdrawal:

If I want my money to last a specified number of years, how much can I withdraw a month?
PV Rate Years
  Monthly Withdrawal

 

7. Withdrawal:

If I withdraw a fixed amount per month, how much will be left after a specified number of years?
PV Rate Years Withdrawal
  Future Value

 

8. Inflation:

What is the affect of inflation over a specified number of years?
PV Rate Years
  Equivalent Amount


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Instructions

For each online calculator, select the values using the dropdown lists. Calculation of the results will take place automatically. The result will appear in the right-most text box (to the right of the green arrow).

The terms or abbreviations used above include:

  • FV - Future Value
  • PV - Present Value
  • Rate - per cent (enter 1, 2, ...)


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Equations

The equations related to compound interest investments are provided below. In cases where a regular payment or withdrawal is involved, there are two equations provided - one for the case where the transaction is made at the start of the time period and one where the transaction is made at the end of the time period.

The online calculators on this page use end-of-period calculations. Investments (or withdrawals) are taken at the start of the period and calculations provide values at the end of the period.

If you look around the web you'll find that most sites with online calculators don't clarify whether their equations apply to first-of-month or end-of-month transactions. However, most online calculators use the end-of-month calculations. The idea is that to save an amount, an investor will accrue the money over the time period and then place it into the interest-earning account at the end of the period.

Online calculators also differ in how they handle the application of interest rates. Interest rates can be applied yearly, monthly, or continuously. In most online calculators interest rates are applied according to the level at which the investment (or withdrawal) is entered. If a monthly value is entered, then interest rates are applied monthly. If a yearly value is entered, then interest rates are applied yearly. That is the approach use in these online calculators.