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 | Download a Palm version of eFunda's loan/lease calculator! |
| Scenario 1: Find the Monthly Payment |
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Interest rate R% is always a yearly figure. However, in most loan situations it is compounded monthly. In this calculator
the monthly payment is calculated by the following formula where r = R/1200:
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| Scenario 2: Find the Interest Rate |
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For given C, P and N, one can only solve the following equation for r by numerical means.
Given the rather smooth behavior of this equation, this calculator employs the Newton-Raphson method with an educated initial guess:
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| Scenario 3: Find the Number of Payments |
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This calculator figures out the number of months N by the following closed-form expression:
Notice that N has to be an integer, so the monthly payment P might be slightly adjusted to satisfy this condition.
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