FinKit 🚀

FinKit is a powerful and lightweight command-line interface (CLI) tool written in Go, designed to help you perform fast and accurate financial operations directly from your terminal.

✨ Key Features

• Currency Conversion: Real-time exchange rates for dozens of currencies.
• Loan Calculation: Detailed amortization, monthly installments, and total cost.
• Compound Interest: Project your investments with monthly contributions.
• Inflation: Calculate the future value of your money and the loss of purchasing power.
• Taxes (Salary): Estimate your net salary after taxes (available for Spain).

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🚀 Quick Installation

If you have Go installed (1.25 or higher):

go install github.com/DAVID-DAM/finkit@latest

Or download the pre-compiled binary for your OS from the Releases page.

Or clone and build manually:

git clone https://github.com/DAVID-DAM/finkit.git
cd finkit && go build -o finkit main.go

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🛠️ Usage Guide and Examples

1. Currency Conversion

Convert amounts between different international currencies with real-time data.

Command:

finkit currency convert <amount> <from> <to>

Example:

finkit currency convert 100 EUR USD

Result:

100.00 EUR = 108.45 USD
Last update: 2026-07-04

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2. Loan Simulation

Calculate the monthly installment and the total cost of a loan.

Command:

finkit loan --amount <amount> --rate <annual_rate> --years <years>

Example:

finkit loan --amount 200000 --rate 3.5 --years 30

Result:

Loan Calculation:

Loan amount:               200000.00
Annual rate:                   3.50%
Loan period:                      30 years
────────────────────────────────────────────────
Monthly payment:              898.09
Total interest:            123312.18
Total cost:                323312.18

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3. Compound Interest

Project the growth of your long-term investments.

Command:

finkit interest compound --initial <initial_capital> --monthly <monthly_contribution> --years <years> --rate <annual_rate>

Example:

finkit interest compound --initial 10000 --monthly 500 --years 10 --rate 7

Result:

Compound Interest Calculation:

Initial investment:         10000.00
Monthly contribution:         500.00
Annual rate:                   7.00%
Investment period:                10 years
────────────────────────────────────────────────
Total invested:             70000.00
Interest earned:            36573.04
Final value:               106573.04

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4. Inflation Calculator

Find out how much value your money will lose in the future due to inflation.

Command:

finkit inflation --initial <amount> --years <years> --rate <annual_inflation>

Example:

finkit inflation --initial 10000 --years 10 --rate 3

Result:

10000.00 today

7440.94 purchasing power in 10 years (3.00% annual inflation)
2559.06 money lost

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5. Net Salary Calculation (Spain)

Calculate your estimated net salary from the gross amount.

Command:

finkit tax salary <gross_salary> <country>

Example:

finkit tax salary 45000 ES

Result:

Gross salary: 45000.00
Estimated taxes: 10450.00
Net salary: 34550.00

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ℹ️ Additional Information

• Currency Data: Provided by Frankfurter API.
• Cache: FinKit saves exchange rates locally to speed up queries and work offline if the data is recent.
• Version: Check your current version with finkit version.
• Update: Keep FinKit up to date with finkit update.
• Help: Use finkit -h or finkit --help at any time to see all available commands and options.

📄 License

This project is under the MIT License. See the LICENSE file for more details.