https://github.com/kfiku/loanjs
Calculate loan in js (browser/node.js) for equal installments, installments decreasing, the sum of interest, etc.
https://github.com/kfiku/loanjs
browserify calculator equal-installments javascript loan
Last synced: about 2 months ago
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Calculate loan in js (browser/node.js) for equal installments, installments decreasing, the sum of interest, etc.
- Host: GitHub
- URL: https://github.com/kfiku/loanjs
- Owner: kfiku
- License: mit
- Created: 2014-10-21T19:58:40.000Z (over 10 years ago)
- Default Branch: master
- Last Pushed: 2023-07-25T00:16:18.000Z (almost 2 years ago)
- Last Synced: 2025-04-12T17:25:50.605Z (about 2 months ago)
- Topics: browserify, calculator, equal-installments, javascript, loan
- Language: JavaScript
- Homepage: http://kfiku.github.io/LoanJS/
- Size: 1.69 MB
- Stars: 29
- Watchers: 2
- Forks: 15
- Open Issues: 1
-
Metadata Files:
- Readme: README.md
- Changelog: CHANGELOG.md
- License: LICENSE
Awesome Lists containing this project
README
# LoanJS
[
](http://packagequality.com/#?package=loanjs)
[](http://badge.fury.io/js/loanjs)
[](https://github.com/kfiku/LoanJS/actions/workflows/node.js.yml)
Super **small** and **fast** module to calculate loan in js (browser/node.js) for **equal**/**decreasing**/**annuity**/**annuityDue** installments, the **sum of interest**, etc, with TypeScript support
## Getting Started
Install with:
```
npm install loanjs
```
#### Calculating Loan:
```js
import { Loan } from 'loanjs';
// or
const { Loan } = require('loanjs');
const loan = new Loan(
1000, // amount
12, // installments number
5, // interest rate
'annuity' // loanType: 'annuity' | 'annuityDue' | 'diminishing' | GetNextInstalmentPartFunction
);
/** returns
{
installments : [
{
capital : number,
interest : number,
installment : number,
remain : number
},
//...
],
amount : number,
interestSum : number,
capitalSum : number,
sum : number
}
*/
```
## Documentation
### Loan
LoanJS.Loan(amount, installmentsNumber, interestRate, loanType)
### Arguments
| Argument | type | default | Description
| ------------------ | -------------- | --------- | ------------------
| amount | number | *required | full amount of Loan
| installmentsNumber | number | *required | how many installments will be (in months)
| interestRate | number | *required | interest rate in percent (ex. 3.5)
| loanType | string or fn | annuity | annuity \| annuityDue \| diminishing \| GetNextInstalmentPartFunction
```ts
interface InstallmentPart {
capital: number;
interest: number;
installment: number;
}
type GetNextInstalmentPartFunction = (
amount: number,
installmentsNumber: number,
interestRateMonth: number,
capitalSum: number
) => InstallmentPart;
```
### Returns
```js
{
installments : [
{
capital : number,
interest : number,
installment : number,
remain : number
}
],
amount : number,
interestSum : number,
capitalSum : number,
sum : number
}
```
## Examples
### typescript example
```ts
import { Loan } from 'loanjs';
const annuityLoan = new Loan(1000, 12, 5, 'annuity');
const annuityDueLoan = new Loan(1000, 12, 5, 'annuityDue');
const diminishingLoan = new Loan(1000, 12, 5, 'diminishing');
const customInstalmentLoan = new Loan(1000, 12, 5, getNext10Instalment);
function getNext10Instalment (amount: number, installmentsNumber: number, capitalSum: number, interestRateMonth: number) {
const capital = rnd(amount / installmentsNumber);
const interest = 10;
const installment = capital + interest;
return { capital, interest, installment };
}
```
### nodejs example
```js
import { Loan } from 'loanjs';
// or
const { Loan } = require('loanjs');
const loan_1 = new Loan(1000, 12, 5, 'diminishing');
// loan on 1 000($) in 12 loanType installments (ex. months) with 5% interest rate
const loan_2 = new Loan(500000, 360, 3.5, 'annuity');
// loan on 500 000($) in 360 equal installments (30 years) with 3.5% interest rate
```
### Browser example:
> You can also render loan as html table
```html
const loan = new LoanJS.Loan(1000, 12, 5, 'annuity');
const div = document.createElement("div");
div.innerHTML = LoanJS.loanToHtmlTable(loan); // loan rendering as html table string
document.body.appendChild(div);
```
more examples [here](https://github.com/kfiku/LoanJS/tree/master/example)
## Similar projects
* [InterestJS](https://github.com/kfiku/InterestJS) - counting regular savings
## Contributing
Im open for contributors :).
## Release History
#### 2023-07-25 v1.1.0
* add `annuityDue` interest rate loan type
* changing the fourth argument `diminishing` to `loanType` (`annuity` | `diminishing` | `annuityDue`), with backward compatibility (false == 'annuity', true == 'diminishing')
* refactor getNextInstalment to be open for extensions
* add option to provide function to loanType to customize instalments counting
#### 2023-06-23 v1.0.11
* add TypeScript types
* code cleanup
* packages update
#### 2017-08-06 v1.0.0
* go to es6
* make dist files
* make 100% covered tests
#### 2016-02-29 v0.1.4
* update dependencies
#### 2015-10-12 v0.1.3
* fixing typo intrest -> interest [#3](https://github.com/kfiku/LoanJS/issues/3)
* update dependencies
#### 2014-11-10 v0.0.4
* update dependencies
#### 2014-11-10 v0.0.2
* now you can use it in node/browserify and browser
## License
Copyright (c) 2023 Grzegorz Klimek
Licensed under the MIT license.