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Percentages in Personal Finance

Finance4 min read

Percentages are the language of money. Whether you're saving for retirement or paying off debt, understanding how percentages work is the single most important skill for financial literacy.

The 50/30/20 Budgeting Rule

One of the most popular budgeting methods relies entirely on percentages. Popularized by Senator Elizabeth Warren, it suggests dividing your after-tax income into three buckets:

50%
Needs
Rent, groceries, utilities, insurance
30%
Wants
Dining out, hobbies, entertainment
20%
Savings
Debt repayment, investments, emergency fund

APR vs. APY: What's the Difference?

You'll often see these two acronyms when looking at bank accounts or loans. They both refer to interest expressed as a percentage, but they measure it differently.

Tip: When borrowing, look for a lower APR. When saving, look for a higher APY.

The Magic of Compound Interest

Albert Einstein reputedly called compound interest the "eighth wonder of the world." It's the principle that you earn interest not just on your initial principal, but also on the accumulated interest from previous periods.

A 7% annual return might not sound like much, but thanks to compounding, your money would double approximately every 10 years (Rule of 72). This is why starting to save early—even small percentages of your income—is so powerful.