Sep-18-2008

how do you figure up your monthly payments of a loan using a calculator?

loan calculator


ive forgot what i learned in 7th grade math

Posted under Loan calculator
  1. Zeina Said,

    First you need to know what your interest rate is & if it’s constant, decreasing, or increasing. Then you divide your loan amount over the number of months in which you have to completely close it, add the interest rate per month & you’ve got it.

  2. rhsaunders Said,

    Depends on the type of calculator. If you have a financial calculator, such as the HP 12-C, the necesary functions are all built in and all you need to do is to press the buttons. If you have a scientific calculator, you can do it using a procedure which I’ll describe in a moment. If your calculator is a four-banger, it is too difficult to do to be a realistic option.

    If you use a scientific calculator, the formula you need is:
    Pmt = (i)(P)/(1-exp(-(n)(i))) where Pmt is the monthly payment, i is the interest rate per month, P is the principal, exp is the exponential function, and n is the number of payments. The formula is not quite exact if n is small, but for the usual loan the error is insignificant.

  3. Helmut Said,

    That’s not a 7th grade problem if you are talking about a real loan with compound interest. You will need a calculator with a x^y key and 1 memory. If you are running Windows 95 or later, your accessory calculator set up as scientific works fine.

    let
    i = MONTHLY interest ((quoted annual interest) / 12),
    P = principle of the loan
    n = number of months
    p =your payment

    then

    p = i*P/(1-1/((1+i)^n))

    fastest keystroke solution is as follows:
    enter annual interest as a decimal.
    press /, enter 12, press =, press MS, press +, press 1, press x^y, enter n, press =, press 1/x, press -, press 1, press =, press +/-, press 1/x, press *, press MR, press *, enter P, press =

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