CalcBusiness

The problem

Running a business means answering the same money questions over and over. What is my margin? What will my paycheck actually be after tax? What should I charge per hour? When is this invoice due, and what late fee can I add?

The answers are scattered across a dozen sites, most of which want an email address first, and many of which will not show you the formula they used.

What it does

Fifty-nine tools in four families, all free and all running locally in your browser.

• Business calculators. Profit margin and markup, breakeven, loan payments, freelance rates, fees. Each shows the formula behind the result and a worked example, so you can check the arithmetic instead of trusting it.
• Tax and take-home pay. Real paycheck after federal tax, FICA and state tax across all 50 US states plus DC, then Canada, the UK and Australia. Rates come from the IRS, CRA, HMRC and ATO, and every page shows the date the data was last verified.
• Invoice and billing documents. Invoices, quotes, receipts, credit notes, purchase orders and deposit invoices as clean PDFs, plus invoice numbering, due dates, late fees and a timesheet that feeds an hourly invoice.
• PDF tools. Merge, split, compress, rotate, convert, sign and fill — entirely in the browser, so contracts and tax forms never leave your device.

No account, no email wall, no trial countdown.

Who it is for

Freelancers, small business owners and anyone running a side project who needs a defensible number quickly — and would rather see the formula than take a result on faith.