DDP Project

This application implements a calculator to get annuity calculations based on compound interest.

It is applicable to many payment scenarios, like car payments, furniture, or small debts.

Initial amount

Using slider you must indicate how much is the initial loan amount, ranging from $50,000.00 to $250,000.00 USD.

Years to pay

Using slider you must indicate how many years do you want to spend paying your loan, ranging from 1 to 5 years.

Payment frequency

You can select from options, which annual frequency of payment you do want (number of payments to make in the year). You can select 12, 6, 4, 3 and 2 payments corresponding to monthly, bimestral, trimestral, quatterly and semi annual frequency.

Annual rate of compound interest

You can select between 12% to 15% compound annual rates of interest to make calculations.

Initial amount of loan

It's the amount of the initial loan in USD.

Total amount of loan (plus interest)

It's the amount of the loan at the end of period, accumulating all interests as if no payment was made. It is equivalente to initial loan amount plus all interest calculated during all period of debt at specified rate.

Amount of interest

It is the total amount minus the initial amout of loan.

Numbers of payments to make.

It is the product of frequency by year, calculating the total quantity of payments to be made during the selected period of years, according to the frequency indicated.

Amount of periodic payment.

It is the calculation of annuity, the periodic amount of payment to be made during the debt period. This is a fixed amount, considering the rules of compound interest.

This calculator applies the formulas corresponding to annuity calculations based on compound interest.

For this application, the type of annuity is simple, certain, pay at due and inmediate.

A loan of $130,000.00 USD to pay in 2 years, making payments every 3 months, with 14% compund annual rate of interest.

loan <- 130000
frequency <- 4
annual.rate <- 0.14
years <- 2

# Number of payments
payments <- years * frequency

# Rate of the period of calculation
period.rate <- annual.rate / frequency

# Annuity (fixed amount of payment)
payment <- (loan*period.rate) / (1-(1+period.rate)^(-payments))