About BizFormula

What BizFormula does

Each page pairs a working calculator with an explanation of the formula behind it. You can work out figures such as profit margin, markup, a break-even point, return on ad spend (ROAS), customer acquisition cost (CAC), return on investment (ROI), sales commission, a pay raise, or hours worked across a week — and see how each number is produced.

Calculators run in your browser. There is no account, and the values you enter are not sent to BizFormula.

Why BizFormula exists

A calculation is more useful when you can see how it was reached. A margin of 25% means little if you are unsure whether it was measured against cost or against price. So alongside the result, each calculator aims to show:

• the formula and what each input means,
• a worked example you can check by hand,
• how to read the result, including negative or zero values,
• the assumptions the calculation depends on,
• where the formula stops being a good description of reality, and
• related calculations that answer the next question.

How our calculators are built

Formulas are written down explicitly, and the calculation code is kept separate from the page layout so it can be tested on its own. Invalid inputs — such as a zero where the formula divides — are caught and explained rather than shown as errors or blank results. Full precision is kept during the calculation; rounding happens only when a number is displayed. Limitations specific to each calculator are listed on its page.

The details are described in the Calculator Methodology.

Who BizFormula is for

The calculators are intended for small-business owners, marketers, e-commerce operators, sales professionals, students learning business metrics, and anyone checking a figure before making a decision. The Pay Raise and Work Hours calculators are intended for employees and managers working out pay changes and time worked.

Informational use and limitations

BizFormula provides informational calculation tools. A result is only as accurate as the numbers entered and the assumptions behind the formula. The tools do not replace accounting, tax, legal, financial, employment-law, or other professional advice. For decisions with significant consequences, check the result against your own records and, where appropriate, with a qualified professional.

Editorial standards

Explanations are written to separate formulas, examples, assumptions, and interpretation clearly, and to avoid presenting arbitrary numbers as universal benchmarks. Errors are corrected when they are found. See the Editorial Policy for how content is created, updated, and corrected.

Calculator methodology

For how inputs are validated, how precision and rounding are handled, which edge cases are covered, and how calculation logic is tested, read the Calculator Methodology.

Contact

Questions, suggestions, and reports of possible errors can be sent to Hello@thebizformula.com. More detail is on the Contact page.