https://github.com/nao1215/cic
cic - compound interest calculator
https://github.com/nao1215/cic
command-line-tool compound-interest server
Last synced: 5 months ago
JSON representation
cic - compound interest calculator
- Host: GitHub
- URL: https://github.com/nao1215/cic
- Owner: nao1215
- License: mit
- Created: 2024-07-19T10:48:11.000Z (almost 2 years ago)
- Default Branch: main
- Last Pushed: 2025-08-12T19:14:02.000Z (10 months ago)
- Last Synced: 2025-10-14T06:35:35.637Z (8 months ago)
- Topics: command-line-tool, compound-interest, server
- Language: Rust
- Homepage:
- Size: 47.9 KB
- Stars: 3
- Watchers: 1
- Forks: 0
- Open Issues: 1
-
Metadata Files:
- Readme: README.md
- Contributing: CONTRIBUTING.md
- Funding: .github/FUNDING.yml
- License: LICENSE
- Code of conduct: CODE_OF_CONDUCT.md
- Security: SECURITY.md
Awesome Lists containing this project
README
[](https://github.com/nao1215/cic/actions/workflows/build.yml)
[](https://github.com/nao1215/cic/actions/workflows/test.yml)
# cic - compound interest calculator
The cic command calculates compound interest. The results of the calculation are output as either a bar graph (`plot.png`) or in JSON format. The cic command has a mode for starting as a server.
The cis calculates the total final amount of the investment based on the input values for the principal, monthly contribution, annual interest rate, and the number of years of contribution.
## Build
```bash
$ cargo build --release
```
## Install
```bash
$ cargo install --path .
```
## Usage
```bash
$ cic --help
cis - Calculates Compound Interest.
Output the results of compound interest calculations as either a line graph image or JSON.
Usage: cic [OPTIONS] [COMMAND]
Commands:
server Starts the server mode
help Print this message or the help of the given subcommand(s)
Options:
-p, --principal The principal at the time you started investing. Defaults to 0
-c, --contribution The monthly contribution amount. Defaults to 1
-r, --rate The annual interest rate (in %). Defaults to 5
-y, --years The number of years for contributions. Defaults to 5
-j, --json Output as JSON. Defaults to false
-h, --help Print help
```
## Example
### Output plot.png
```bash
$ cic --principal 1000000 --contribution 100000 --rate 10 --years 10
```
### Output json
```shell
$ ./target/debug/cic --principal 1000000 --contribution 100000 --rate 10 --years 5 --json
[
{
"year": 1,
"principal": 1000000.0,
"annual_contribution": 1200000.0,
"total_contribution": 1200000.0,
"annual_interest": 100000.0,
"total_interest": 100000.0,
"total_amount": 2300000.0
},
{
"year": 2,
"principal": 1000000.0,
"annual_contribution": 1200000.0,
"total_contribution": 2400000.0,
"annual_interest": 230000.0,
"total_interest": 330000.0,
"total_amount": 3730000.0
},
{
"year": 3,
"principal": 1000000.0,
"annual_contribution": 1200000.0,
"total_contribution": 3600000.0,
"annual_interest": 373000.0,
"total_interest": 703000.0,
"total_amount": 5303000.0
},
{
"year": 4,
"principal": 1000000.0,
"annual_contribution": 1200000.0,
"total_contribution": 4800000.0,
"annual_interest": 530300.0,
"total_interest": 1233300.0,
"total_amount": 7033300.0
},
{
"year": 5,
"principal": 1000000.0,
"annual_contribution": 1200000.0,
"total_contribution": 6000000.0,
"annual_interest": 703330.0,
"total_interest": 1936630.0,
"total_amount": 8936630.0
}
]
```
### Sever mode
```shell
$ cic server
Starting server, port: 8080
POST /compound-interests
```
```shell
$ curl -X POST "http://localhost:8080/compound-interests" \
-H "Content-Type: application/json" \
-d '{"principal": 1000000, "contribution": 100000, "rate": 10, "years": 2}' | jq .
[
{
"annual_contribution": 1200000.0,
"annual_interest": 100000.0,
"principal": 1000000.0,
"total_amount": 2300000.0,
"total_contribution": 1200000.0,
"total_interest": 100000.0,
"year": 1
},
{
"annual_contribution": 1200000.0,
"annual_interest": 230000.0,
"principal": 1000000.0,
"total_amount": 3730000.0,
"total_contribution": 2400000.0,
"total_interest": 330000.0,
"year": 2
}
]
```
## License
MIT
## Contributing
First off, thanks for taking the time to contribute! ❤️ See [CONTRIBUTING.md](./CONTRIBUTING.md) for more information.
Contributions are not only related to development. For example, GitHub Star motivates me to develop!
[](https://star-history.com/#nao1215/cic&Date)
## Side note
The cic command is my first project in Rust. I am using it to learn how to write and structure projects in Rust.
### Why did I choose the theme of compound interest?
In Japan, the small amount investment tax exemption system (NISA) started gaining traction in 2024. I was fortunate enough to get involved in a NISA app at work.
This led me to develop an interest in investments. So, it's not surprising that I chose compound interest as my theme.