The Math Behind Money
TheRichGuyMath is an independent personal-finance education website created to make money easier to understand.
Personal finance can feel complicated because financial decisions often involve unfamiliar terms, percentages, rules, and calculations. Our goal is to break those concepts down into plain English and show the numbers behind them.
We cover topics including:
- Credit and credit cards
- Debt
- Budgeting and saving
- Banking
- Investing
- Financial planning
- Passive income
- Personal-finance calculations and tools
Our approach is simple:
Explain the concept. Show the math. Use real-world examples. Explain the limitations.
Why TheRichGuyMath Exists
Many financial websites tell readers what they should do without fully explaining why.
TheRichGuyMath takes a different educational approach.
Instead of simply saying that someone should save more, reduce debt, or invest, we try to explain the underlying financial concepts and calculations so readers can understand how the decision works.
For example, instead of simply saying that a $300 credit card balance represents 15% utilization on a $2,000 credit limit, we can show the calculation:
$300 ÷ $2,000 × 100 = 15%
That is the idea behind “The Math Behind Money.”
How We Research Financial Content
We prioritize reliable and authoritative sources, particularly primary sources and government or regulatory organizations when they are relevant to the subject.
Depending on the topic, sources may include organizations such as:
- U.S. Securities and Exchange Commission (SEC)
- Consumer Financial Protection Bureau (CFPB)
- Federal Reserve
- Federal Deposit Insurance Corporation (FDIC)
- Financial Industry Regulatory Authority (FINRA)
- Internal Revenue Service (IRS)
- U.S. Department of the Treasury
- Bureau of Labor Statistics (BLS)
We may also use reputable financial and educational sources when they provide useful context or additional data.
Sources are selected based on their relevance and reliability rather than simply because they support a particular conclusion.
Our Approach to Financial Calculations
When an article involves financial math, we aim to make the important assumptions visible.
Depending on the calculation, this may include:
- Interest rate
- Starting balance
- Contribution amount
- Payment amount
- Time period
- Compounding frequency
- Inflation assumptions
- Fees
- Taxes
- Other relevant variables
When a calculation is an estimate, we identify it as an estimate.
When a calculator has limitations, we explain those limitations rather than presenting the result as a guaranteed outcome.
Original Financial Tools
One of the core goals of TheRichGuyMath is to create practical tools that allow readers to apply financial concepts to their own numbers.
These may include calculators and organizers for subjects such as:
- Emergency funds
- Debt repayment
- Credit-card interest
- Compound interest
- Budgeting
- Savings goals
- Car affordability
- Other personal-finance decisions
Our tools are educational. They perform calculations based on the information entered by the user and do not replace individualized financial, tax, legal, or investment advice.
Our Editorial Philosophy
We believe financial education should be:
Clear — Complex financial concepts should be explained in plain English.
Evidence-based — Important factual claims should be supported by reliable sources.
Transparent — Assumptions, limitations, and methodology should be explained when they affect the conclusion.
Practical — Readers should be able to understand how a concept applies to real financial situations.
Honest — We do not present ourselves as professionals with credentials we do not hold.
What TheRichGuyMath Is Not
TheRichGuyMath is an independent financial education website.
We are not a bank, brokerage, investment adviser, accounting firm, law firm, or financial planning firm.
Our content is intended for educational and informational purposes. It is not individualized financial, investment, tax, accounting, or legal advice.
When a financial decision involves circumstances that require professional advice, readers should consider consulting an appropriately qualified professional.
Our Commitment to Accuracy
Financial information can change.
Interest rates, tax rules, regulations, contribution limits, financial products, and other information may change over time. We therefore aim to review and update content when material information changes.
If we discover a factual, mathematical, or other substantive error, we work to correct it.
For more information, see our [Editorial & Research Policy] and [Corrections & Updates Policy].
Who Runs TheRichGuyMath?
TheRichGuyMath is founded and written by Max Fonji.
You can learn more about the author, his areas of focus, and the editorial approach used throughout the site on the About The Author page.
Our Goal
The goal of TheRichGuyMath is not to tell readers what financial decision they must make.
It is to help readers understand the numbers, concepts, tradeoffs, and risks well enough to make more informed decisions for themselves.
That’s the math behind money.
Last Reviewed: September 2026