Free Financial Calculators
Every calculator here works without an account, and nothing you type is sent anywhere — the arithmetic runs in your browser. Each one has its own page explaining what it assumes and how to read the result.
Saving and growth
- Compound interest calculator — what a starting balance and a monthly contribution become over time, and how much of the total is growth rather than money you put in.
- Emergency fund calculator — how many months of essential expenses you should hold, how far along you are, and how long the rest will take.
- Inflation calculator — what a sum will cost later, what a future amount is worth in today's money, and how much purchasing power is lost along the way.
Budgeting
- 50/30/20 budget calculator — take-home pay split into needs, wants and savings, and what to do when your fixed costs do not fit inside half.
Borrowing and housing
- Loan amortization calculator — a payment-by-payment schedule showing where the interest goes and what paying extra principal actually saves.
- Rent vs. buy calculator — the full cost of each, including the ones the mortgage payment hides, and the year buying overtakes renting.
More than a single calculation
The pages above each answer one question. Three places on the site go further:
- Finance tools and debt tools — the same calculators alongside the rest of each area, including the debt payoff and refinance comparisons that have no standalone page.
- Retirement planning — projections run in today's dollars against randomly drawn returns rather than one smooth rate, which is the honest way to read a thirty-year number.
- The budget planner — with an account, a budget built around your real pay dates rather than a calendar month.
For the reasoning behind the figures rather than the arithmetic, start with the personal finance guide or the debt guide. How all of it is sourced and kept current is on the about page.