amort.table {FinancialMath}

Amortization Table

Description

Produces an amortization table for paying off a loan while also solving for either the number of payments, loan amount, or the payment amount. In the amortization table the payment amount, interest paid, principal paid, and balance of the loan are given for each period. If n ends up not being a whole number, outputs for the balloon payment, drop payment and last regular payment are provided. The total interest paid, and total amount paid is also given. It can also plot the percentage of each payment toward interest vs. period.

Usage

amort.table(Loan=NA,n=NA,pmt=NA,i,ic=1,pf=1,plot=FALSE)

Arguments

Loan

loan amount

n

the number of payments/periods

pmt

value of level payments

i

nominal interest rate convertible ic times per year

ic

interest conversion frequency per year

pf

the payment frequency- number of payments per year

plot

tells whether or not to plot the percentage of each payment toward interest vs. period

Details

Effective Rate of Interest: eff.i=(1+\frac{i}{ic})^{ic}-1

j=(1+eff.i)^{\frac{1}{pf}}-1

Loan=pmt*{a_{\left. {\overline {\, n \,}}\! \right |j}}

Balance at the end of period t: B_t=pmt*{a_{\left. {\overline {\, n-t \,}}\! \right |j}}

Interest paid at the end of period t: i_t=B_{t-1}*j

Principal paid at the end of period t: p_t=pmt-i_t

Total Paid=pmt*n

Total Interest Paid=pmt*n-Loan

If n=n^*+k where n^* is an integer and 0<k<1:

Last regular payment (at period n^*) =pmt*{s_{\left. {\overline {\, k \,}}\! \right |j}}

Drop payment (at period n^*+1) =Loan*(1+j)^{n^*+1}-pmt*{s_{\left. {\overline {\, n^* \,}}\! \right |j}}

Balloon payment (at period n^*) =Loan*(1+j)^{n^*}-pmt*{s_{\left. {\overline {\, n^* \,}}\! \right |j}}+pmt

Value

A list of two components.

Schedule

A data frame of the amortization schedule.

Other

A matrix of the input variables and other calculated variables.

Note

Assumes that payments are made at the end of each period.

One of n, Loan, or pmt must be NA (unknown).

If pmt is less than the amount of interest accumulated in the first period, then the function will stop because the loan will never be paid off due to the payments being too small.

If pmt is greater than the loan amount plus interest accumulated in the first period, then the function will stop because one payment will pay off the loan.

Author(s)

Kameron Penn and Jack Schmidt

See Also

amort.period

annuity.level

Examples

amort.table(Loan=1000,n=2,i=.005,ic=1,pf=1)

amort.table(Loan=100,pmt=40,i=.02,ic=2,pf=2,plot=FALSE)

amort.table(Loan=NA,pmt=102.77,n=10,i=.005,plot=TRUE)