This is a PHP SDK for calculating loan amortization Calculates the total interest, repayment amount as well as the repayment schedule
- Flat Rate Interest
- This is interest type where the interest rate for each period is computed as a percentage of the loan principal amount
- The loan interest is constant over the entire repayment period
- Interest on Reducing Balance
- In this case, instead of computing interest on the principal amount, the interest for each period is calculated as a percentage of the balance on principal repayments at at that time
- The user thus pays less interest in later periods when their loan balance reduces as compared in the amount they'd pay at the start of the loan repayment schedle
- Loan amortization basically describes the repayment schedule spread over a given duration
- The following types are supported:
- Even Principal Repayment: This is a repayment plan where the principal repayment remains constant over the entire repayment duration
- Even Installment Repayment: This is a repayment plan where the total repayment remains constant over the entire repayment duration
- Loan amortization types depend on the interest type:
- Flat Rate Interest: Amortization type doesn't really matter. The repayments will have both equal installment and principal and interest repayments for the entire repayment duration
- Interest on Reducing Balance: Supports both types. Either of them can be used at a time
The package supports three types of grace on repayments
- Grace on Principal Repayments: When applied, the principal repayments for the set period are deferred to a later period. For instance, if grace on principal repayments is set to 2, then the first two installments will have principal repayments of 0 and the principal amounts recouped through the remaining installments
- Grace on Interest Repayments: When applied, the interest repayments for the set period are deferred to a later period. For instance, if grace on interest repayments is set to 2, then the first two installments will have the interest repayments of 0 and the interests will be collected in the last two installments.
- Grace on Interest: This is a conditional grace applied to interest collected. If set, the interest for the specified period is zero-rated ie no interest is paid for that period. For instance, one can set if a loan is repaid within a year, then the first two months interests will be zero-rated hence the user only pays the principal amounts for those first two months.
composer require phelix/loan-amortization
The test is more of a visualization tool than an actual test.
vendor/bin/phpunit test
As you go through the sample code samples, please note that anywhere with periods, the period types can take any of the values: days, weeks, months and years . Everything in lower case and plural.
Loan Details:
- Loan Principal = 50,000.00
- Interest Rate = 12% per year
- Loan duration = 1 week
- Repayment Schedule = 1 repayment every 2 days
<?php
use Phelix\LoanAmortization\ScheduleGenerator;
$interestCalculator = new ScheduleGenerator();
$interestCalculator
->setPrincipal(50000)
->setInterestRate(12, "yearly", ScheduleGenerator::FLAT_INTEREST) // note the interest type
->setLoanDuration(1, "weeks") // could be "years" to have it in years or "months" to have it in months
->setRepayment(1,2, "days")
->generate();
print "\nTotal Interest = {$interestCalculator->interest} \n";
print "Effective Interest Rate = {$interestCalculator->effective_interest_rate} \n";
print "Total Repayable amount = {$interestCalculator->amount} \n";
print "Number of Installments = {$interestCalculator->no_installments} \n";
print "Repayment Frequency = {$interestCalculator->repayment_frequency} \n";
print "Amortization Schedule: \n";
print_r($this->interestCalculator->amortization_schedule);
// Sample Schedule Response:
Array
(
[0] => Array
(
[principal_repayment] => 14285.71,
[interest_repayment] => 32.88,
[total_amount_repayment] => 14318.59,
[principal_repayment_balance] => 35714.29
),
[1] => Array
(
[principal_repayment] => 14285.71,
[interest_repayment] => 32.88,
[total_amount_repayment] => 14318.59,
[principal_repayment_balance] => 21428.58,
),
[2] => Array
(
[principal_repayment] => 14285.71,
[interest_repayment] => 32.88,
[total_amount_repayment] => 14318.59,
[principal_repayment_balance] => 7142.87,
),
[3] => Array
(
[principal_repayment] => 7142.87,
[interest_repayment] => 16.43,
[total_amount_repayment] => 7159.3,
[principal_repayment_balance] => 0
)
);Loan Details:
- Loan Principal = 50,000.00
- Interest Rate = 12% per year
- Loan duration = 1 week
- Repayment Schedule = 1 repayment every 2 days
<?php
use Phelix\LoanAmortization\ScheduleGenerator;
$interestCalculator = new ScheduleGenerator();
$interestCalculator
->setPrincipal(50000)
->setInterestRate(12, "yearly", ScheduleGenerator::INTEREST_ON_REDUCING_BALANCE) // note the interest type
->setLoanDuration(1, "weeks")
->setRepayment(1,2, "days")
->setAmortization(ScheduleGenerator::EVEN_PRINCIPAL_REPAYMENT) // note the amortization type
->generate();
print "\nTotal Interest = {$interestCalculator->interest} \n";
print "Effective Interest Rate = {$interestCalculator->effective_interest_rate} \n";
print "Total Repayable amount = {$interestCalculator->amount} \n";
print "Number of Installments = {$interestCalculator->no_installments} \n";
print "Repayment Frequency = {$interestCalculator->repayment_frequency} \n";
print "Amortization Schedule: \n";
print_r($this->interestCalculator->amortization_schedule);
// Sample Response
Array
(
[0] => Array
(
[principal_repayment] => 21428.57,
[interest_repayment] => 49.32,
[total_amount_repayment] => 21477.89,
[principal_repayment_balance] => 28571.43
),
[1] => Array
(
[principal_repayment] => 21428.57,
[interest_repayment] => 28.18,
[total_amount_repayment] => 21456.75,
[principal_repayment_balance] => 7142.86
),
[2] => Array
(
[principal_repayment] => 7142.86,
[interest_repayment] => 7.05,
[total_amount_repayment] => 7149.91,
[principal_repayment_balance] => 0
)
);
Loan Details:
- Loan Principal = 50,000.00
- Interest Rate = 12% per year
- Loan duration = 1 week
- Repayment Schedule = 1 repayment every 2 days
<?php
use Phelix\LoanAmortization\ScheduleGenerator;
$interestCalculator = new ScheduleGenerator();
$interestCalculator
->setPrincipal(50000)
->setInterestRate(12, "yearly", ScheduleGenerator::INTEREST_ON_REDUCING_BALANCE) // note the interest type
->setLoanDuration(1, "weeks")
->setRepayment(1,2, "days")
->setAmortization(ScheduleGenerator::EVEN_INSTALLMENT_REPAYMENT) // note the amortization type
->generate();
print "\nTotal Interest = {$interestCalculator->interest} \n";
print "Effective Interest Rate = {$interestCalculator->effective_interest_rate} \n";
print "Total Repayable amount = {$interestCalculator->amount} \n";
print "Number of Installments = {$interestCalculator->no_installments} \n";
print "Repayment Frequency = {$interestCalculator->repayment_frequency} \n";
print "Amortization Schedule: \n";
print_r($this->interestCalculator->amortization_schedule);
// Sample Response
Array
(
[0] => Array
(
[principal_repayment] => 16650.23,
[interest_repayment] => 49.32,
[total_amount_repayment] => 16699.55,
[principal_repayment_balance] => 33349.77
),
[1] => Array
(
[principal_repayment] => 16666.66,
[interest_repayment] => 32.89,
[total_amount_repayment] => 16699.55,
[principal_repayment_balance] => 16683.11,
),
[2] => Array
(
[principal_repayment] => 16683.11,
[interest_repayment] => 16.45,
[total_amount_repayment] => 16699.55,
[principal_repayment_balance] => 0
)
);Loan Details:
- Loan Principal = 50,000.00
- Interest Rate = 12% per year
- Loan duration = 1 week
- Repayment Schedule = 1 repayment every 2 days
<?php
use Phelix\LoanAmortization\ScheduleGenerator;
$interestCalculator = new ScheduleGenerator();
$interestCalculator
->setPrincipal(50000)
->setInterestRate(12, "yearly", ScheduleGenerator::INTEREST_ON_REDUCING_BALANCE) // note the interest type
->setLoanDuration(1, "weeks")
->setRepayment(1,2, "days")
->setAmortization(ScheduleGenerator::EVEN_INSTALLMENT_REPAYMENT) // note the amortization type
->setGraceOnPrincipalRepayment(2) // note the grace period. First two principals' payment deferred
->setGraceOnInterestRepayment(1) // note the grace period. First month interest payment is deferred
->setGraceOnInterest(5, "days", 2, "days") // not how this is set. It reads: If you repay entire loan within 5 days, then no interest will be charged for the first two days
->generate();
print "\nTotal Interest = {$interestCalculator->interest} \n";
print "Effective Interest Rate = {$interestCalculator->effective_interest_rate} \n";
print "Total Repayable amount = {$interestCalculator->amount} \n";
print "Number of Installments = {$interestCalculator->no_installments} \n";
print "Repayment Frequency = {$interestCalculator->repayment_frequency} \n";
print "Amortization Schedule: \n";
print_r($this->interestCalculator->amortization_schedule);- Phelix Juma (jumaphelix@kuzalab.com)