Where to start

Most-used BoringToolsKit tools

The calculators people come back to for money, home, school, and everyday math — a curated starting point for new visitors. We do not collect personal usage data, so this list reflects the tools that solve the most common needs, not per-user tracking.

Paycheck After-Tax Calculator

Take-home pay after federal, state, and FICA withholding.

Mortgage Payment Calculator

Principal, interest, taxes, insurance, and PMI.

Percentage Calculator

Percent of, change, and difference.

Compound Interest Calculator

Growth with compounding and contributions.

General Scientific Calculator

The classic keypad for everyday math.

Credit Card Payoff Calculator

Payoff timeline and interest with extra payments.

Unit Converter

Length, weight, volume, temperature, and more.

Time Card Calculator

Work hours, breaks, and overtime totals.

Flooring Calculator

Materials, waste, and cost for flooring projects.

Sales Tax Calculator

Add or extract sales tax with state rates.

Not sure where to start?

Use the searchable catalogue of all 841 tools, browse by category, or read a practical guide for the assumptions behind the math.