Free Online Tools and Calculators for Finance, Development, Health, Math, Physics, and Everyday Planning

Start with the category that fits your task, then open the exact calculator, converter, or utility you need. The goal is to help you get to the right tool quickly without digging through unrelated pages.

💰⚙️💪📐📅⚛️399 tools
Category hub11 topic hubs123 live tools

Finance calculators for mortgages, taxes, debt payoff, retirement, insurance, and cash-flow planning

Start here if you are buying a home, planning paycheck withholding, paying down debt, comparing insurance costs, or working through a broader money decision.

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Mortgage & housing cost planning

Estimate payments, affordability, refinancing, rent-versus-buy tradeoffs, and ownership costs.

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Debt payoff & credit strategy

Compare payoff order, balance reduction pace, credit-card interest drag, and debt-free timelines.

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Tax & paycheck planning

Move from withholding and net pay checks into bonus, contractor, payroll-tax, and refund planning.

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Investing & retirement planning

Keep retirement savings, compound growth, dividends, and long-horizon money planning in one path.

See all finance calculators

Start here for broader discovery, then move into one narrower topic hub or tool page.

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Choose the category that matches what you are trying to do

If you already know the kind of task you need help with, start with the closest category below. That gets you to a smaller, more useful set of tools faster, whether you are comparing mortgage costs, cleaning up JSON, checking calorie targets, working through math homework, planning a trip budget, or solving a physics formula.

Finance

Finance calculators for home buying, taxes, debt payoff, retirement, and investing

If you are comparing mortgage payments, checking home affordability, planning paycheck withholding, working through bonus or 1099 taxes, planning debt payoff, or estimating long-term savings, start here. Finance keeps housing, loans, taxes, retirement, insurance, and investing tools together so it is easier to move from one money question to the next.

Good when you know the task is financial but you have not picked the exact mortgage, tax, paycheck, debt, or retirement calculator yet.

Developer

Developer tools for JSON, APIs, encoding, and quick code tasks

Use Developer when you are formatting JSON, building or testing requests, decoding text, checking tokens, or generating values while coding. It pulls together the small browser-based utilities developers reach for again and again.

Useful when you know the job, but not the exact tool name.

Health

Health calculators for BMI, calories, macros, pregnancy, and sleep

Start here if you are checking BMI, setting calorie targets, splitting macros, tracking pregnancy dates, or planning sleep. Health keeps the most common wellness and fitness calculators together so related checks are easy to find.

Especially helpful when one check leads naturally to another, like BMI to body fat or calories to TDEE.

Math

Math calculators for percentages, geometry, statistics, and study help

Use Math for percentages, fractions, triangles, averages, statistics, and other classroom or day-to-day calculations. It keeps related problem types together so you can move quickly when one question leads to the next step.

A good place to begin for homework, tutoring, exam prep, and quick number checks.

Everyday

Everyday calculators for dates, bills, rent split, travel cost, and routine planning

Start here for business days, electricity costs, rent split, fuel costs, mileage, countdowns, and other practical planning tasks. These are the tools people usually want for quick day-to-day answers at home, at work, or while planning a trip.

Best for practical tasks that do not fit neatly into finance, math, or health.

Physics

Physics calculators for motion, circuits, heat, and formula checks

Use Physics for velocity, force, electricity, heat, gas-law, and other formula-based calculations. It is useful for students, lab work, and quick checks when you want the right calculator without hunting through notes or a textbook.

Start here when you know the topic, but still need to find the exact formula tool.

Use the homepage in three quick moves

Treat the homepage like a starting map. Pick the closest category here, move into the matching topic hub, and only then open the exact tool. That keeps both users and internal links focused on one problem at a time.

Start broad, narrow with the topic hub

Open the closest category first, then use its topic hub to narrow down to the exact calculator you need.

Use the homepage for orientation, not for every tool

The homepage is meant to help you choose the right section quickly. The deeper tool discovery happens on the category and topic pages.

Keep related checks together

If one question leads to another, stay inside the same category so related calculators, tutorials, and FAQs stay in context.

Latest Representative Tools By Category

Start with the category that matches your task, or jump straight into a newer tool if you already know what you want to open.

Finance
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Home buying, tax withholding, paycheck planning, debt payoff, retirement, investing, and insurance tools in one place.

Developer
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JSON tools, API helpers, encoders, generators, and other browser-based developer utilities.

Health
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BMI, calories, macros, pregnancy, sleep, and everyday wellness calculators.

Percentages, fractions, geometry, statistics, and general study calculators.

Everyday
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Dates, bills, shared costs, shopping, and travel-planning tools for everyday tasks.

Physics
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Motion, circuits, heat, and formula calculators for class, lab, and quick checks.