About InvoiceMaker
A small set of finance tools for people who invoice their own clients, built to be readable rather than clever.
Last updated 2026-09-05.
Why this exists
Invoicing tools are usually sold as subscriptions with a client database, a payment gateway and a reporting dashboard attached. That is the right product for a growing agency and the wrong one for someone who sends four invoices a month and wants to know whether the last project was actually profitable. InvoiceMaker is deliberately the smaller thing: four calculators and a document generator, no account, no trial, no data collection.
How it works
Everything runs as JavaScript inside your browser. There is no server-side component that receives your invoice, which means there is no database of client names, no logo storage bucket and no export feature to worry about. Drafts persist because the browser writes them to its own local storage under keys prefixed invoicemaker:v1:, and the “clear saved draft” button deletes them.
PDFs are produced by a layout engine that draws text as vectors, rather than by photographing the page and embedding the image. The practical result is a file that prints sharply, can be searched, and can be parsed by the accounts payable software on the other end.
The tools
- Invoice Generator — Fill in the form, upload your logo, and download a clean vector PDF invoice. Drafts save automatically in your browser.
- Profit Margin Calculator — Turn cost and revenue into gross margin, markup, net profit and net margin so you can price a project before you quote it.
- Sales Tax, VAT & GST Calculator — Add tax on top of a net price, or work backwards from a tax-inclusive total. Preset rates for 5%, 10%, 18% and 20%.
- Late Payment Fee Estimator — Compare daily simple interest against daily compound interest on an overdue invoice, with a grace period and optional flat fee.
What this is not
These tools do arithmetic on the numbers you give them. They do not know your jurisdiction, your registration status, your accounting basis or the terms of your contract. A tax rate typed into a calculator is not tax advice, and an interest figure is not a legal entitlement. Rates, thresholds and statutory late-payment rules change, and they differ by country and often by state or province. Check anything consequential with a qualified accountant or lawyer in your own jurisdiction before you rely on it.
Corrections and requests
If a formula looks wrong, a currency is missing or a field would be more useful with a different label, that feedback is genuinely welcome. Write to support@invoicemaker.website with the numbers you entered and what you expected, and it will be checked against the formula shown under the tool.