About MoneyMathKit

Last updated: June 4, 2026

MoneyMathKit is a small, focused collection of free finance calculators. The goal is simple: give you a fast, trustworthy answer to a common money question, without an account, a paywall, or twelve interstitial pop-ups in the way.

What's here

• Mortgage Calculator — monthly payment, full amortization schedule, PMI, extra-payment savings, and refinance break-even.
• Compound Interest Calculator — project investment growth with monthly contributions, variable compounding frequency, and inflation adjustments.
• Percentage Calculator — find X% of Y, percent change, increase/decrease, and percent error.
• Tip Calculator — tip amount and per-person totals with bill splitting and quick percentage presets.
• Salary Calculator — convert annual salary to hourly and see take-home pay after federal, state, and FICA taxes with a pay-period breakdown.

How the calculators work

Every calculator runs in your browser using well-known standard formulas. Nothing you type leaves your device. There is no signup, no account, and no stored history of your inputs.

The results are intended as informational starting points, not financial advice. For decisions that affect your money in a meaningful way — a mortgage application, a retirement plan, a tax filing — talk to a qualified professional who knows your full situation.

Who runs MoneyMathKit

MoneyMathKit is built and maintained by Diego, an independent software developer based in San Antonio, Texas. It's part of a broader effort to publish small, dependable utility tools that just work on a phone or a laptop the first time you open them.

How it stays free

The site is supported by display advertising. Ads are clearly separated from the calculators and the underlying math; they do not influence results in any way. See the Privacy Policy for details on how advertising and analytics work here.

Contact

Suggestions, corrections, or partnership questions: diego@mindgap.tech.