Create and Print Professional Invoices for Free Create simple invoices with line items, tax calculations, and print-ready formatting.

Under the hood, it utilizes React state management to store form data for businesses, clients, and line items, including description, quantity, and unit price. The subtotal calculation is performed by multiplying the quantity by the rate for each line item, while tax is computed by applying the specified tax rate to the subtotal. This tool relies on JavaScript's built-in `Date` object to handle date-related operations, such as setting the invoice date and due date. When printing, it leverages the browser's `window.print()` API, in conjunction with specific `@media print` CSS rules, to generate a clean and formatted output. The print template itself is defined using HTML and CSS, allowing for precise control over the layout and styling of the printed invoice. Additionally, it employs the `useState` and `useRef` hooks from React to manage state and references to DOM elements, such as the print template container. The code also uses TypeScript to define interfaces, like the `LineItem` interface, which helps ensure type safety and maintainability. Furthermore, it incorporates CSS styles and classes, including those defined in the `glass-card` and `glass-input` components, to achieve a visually appealing design. The tool's calculation logic is based on simple arithmetic operations, making it efficient and easy to understand. It also uses the `toLocaleString` method to format currency values according to the user's locale settings, providing a more personalized experience. Overall, the combination of React, JavaScript, HTML, CSS, and TypeScript enables this tool to provide a robust and user-friendly invoice generation experience.