All Free Online Calculators & Tools

29 free tools across health, finance, time, digital, and life. All instant, all free, no signup. CalcPool tools are built on documented, checked methodology — established formulas for math and finance tools, peer-reviewed research where a health or science claim needs it. Every tool works on any device and never sends your personal data anywhere. Browse all 29 tools below, featured and trending picks first, or jump directly to a category using the links at the bottom of this page.

All freeNo signupInstant results
Showing 29 Calculators
📊 Sorted by popularity🔥 Updated daily
Trending New

Binary ↔ Decimal Converter

Easily convert numbers between binary (base 2) and decimal (base 10) systems. Perfect for programmers, students, and anyone learning how computers work.

Convert between binary and decimal instantly
Trending New

Binary ↔ Hexadecimal Converter

Easily convert numbers between binary (base 2) and hexadecimal (base 16) systems. Essential for programmers, web developers, and computer science students.

Convert between binary and hexadecimal instantly
Trending New

Binary ↔ Octal Converter

Easily convert numbers between binary (base 2) and octal (base 8) systems. Useful for computing and digital electronics.

Convert between binary and octal instantly
Trending

Burnout Risk Calculator

Answer 10 science-backed questions about your work, sleep, and stress to get your burnout risk score and a personalised recovery plan.

How close are you to burning out?
Trending

Calorie Deficit Calculator

Calculate your calorie deficit in three steps. Get your TDEE, daily calorie target, macro breakdown, and a week-by-week weight-loss projection that adjusts for the drop in metabolism as you lose weight.

Your daily calorie target — and a timeline that accounts for metabolic slowing.
Trending New

Compound Interest Calculator

Calculate compound interest on any investment or savings. See your final balance, total interest earned, and year-by-year growth — with optional monthly contributions. The most powerful free money calculator online.

Watch your money grow exponentially over time.
Trending

Cosmic Age Calculator

Discover your age in cosmic units — on every planet in the solar system, in light-years, and as a fraction of the universe's 13.8 billion year history.

How old are you in the universe?
Trending

Daily Hydration Schedule

Get a personalised hourly drinking schedule based on your weight, wake time, and activity level. Stop guessing about hydration. Get a science-backed hourly plan for today.

Not just how much — exactly when to drink water today.
Trending

Days Until Calculator

Live countdown to any event — Eid, Christmas, birthdays, exams, holidays, Ramadan. Add multiple events and watch the days, hours, minutes, and seconds tick in real time.

Countdown to anything that matters.
Trending

Deadline Countdown Timer

A live countdown timer for any deadline — exams, project submissions, work presentations, personal goals. Set multiple deadlines and watch the clock tick in days, hours, minutes, and seconds.

See exactly how much time you have left.
Trending New

Decimal ↔ Hexadecimal Converter

Easily convert numbers between decimal (base 10) and hexadecimal (base 16) systems. Essential for web developers working with colour codes and programmers debugging memory addresses.

Convert between decimal and hexadecimal instantly
Trending New

Decimal ↔ Octal Converter

Easily convert numbers between decimal (base 10) and octal (base 8) systems. Useful for understanding Unix/Linux file permissions and legacy computing systems.

Convert between decimal and octal instantly
Trending New

Discount Calculator

Free discount calculator with 4 modes: standard discount, stacked coupons, reverse (find original price or % off), and shopping cart with multiple items. Works in any currency with VAT support.

Calculate any discount, stack coupons, and find original prices instantly.
Trending

Electricity Bill Calculator

Find out exactly how much each appliance costs you per day, month, and year. Finally understand your electricity bill.

Which appliance is eating your money?
Trending

Exact Age Calculator

Your precise age in years, months, weeks, days, hours, minutes, and live seconds. Find what day of the week you were born, your next metric birthday (10,000 days, 1 billion seconds), a multi-year birthday-weekday forecast, and a downloadable age card.

How old are you — down to the second, the weekday, and the milestone?
Trending New

Hexadecimal ↔ Octal Converter

Easily convert numbers between hexadecimal (base 16) and octal (base 8) systems. Useful for low-level programming, computing systems, and when working with different number representations.

Convert between hexadecimal and octal instantly
Trending New

Inflation Impact Calculator

Calculate the real impact of inflation on any amount of money over any time period. See how much purchasing power you have lost — and what you need to earn today to match what you earned before.

See exactly how much your money has lost in value.
Trending

Life Progress Bar

See your entire life visualised as a grid of weeks, calculated from exact dates rather than a rough approximation. Adjust for your country's life expectancy or your own lifestyle, download a shareable poster, and see how many summers, Sundays, and birthdays remain — all calculated privately in your browser.

How much of your life have you actually lived?
Trending

Loan EMI Calculator

Calculate your EMI for any home loan, car loan, or personal loan. See total interest, a full amortisation schedule, how a lump-sum prepayment can shorten your loan or lower your EMI, an EMI-to-income affordability check, and a side-by-side comparison against a second loan offer.

Know your exact monthly payment before you borrow.
Trending New

Margin Calculator

Calculate gross margin, net margin, and markup for any product or service. Compare against real industry benchmarks, analyse multiple products simultaneously, and find your break-even point. The most complete free margin calculator online.

Calculate profit margin, markup, and break-even — all in one place.
Trending

Phone Life Thief Calculator

Calculate exactly how many days, weeks, and years of your life you have lost and will lose to your phone screen — based on your daily screen time.

How much of your life has your phone stolen?
Trending

Real Hourly Wage Calculator

Your salary looks good on paper. After tax, commute time, work prep, decompression, unpaid overtime, and job-related expenses — what is your real hourly rate? Enter your numbers and find out.

What do you actually earn per hour of your life?
Trending New

Salary to Daily Rate Calculator

Convert any annual, monthly, or weekly salary into a precise daily rate, hourly rate, and contractor equivalent — or work the other way, from a day rate to its salary equivalent. Simple, adjustable working-day settings.

Know your exact value per day, per hour, and per minute.
Trending

Sleep Calculator

Calculate the best time to sleep or wake up based on 90-minute sleep cycles, an exact custom duration, or your own age group. Never wake up groggy again.

Wake up refreshed — every single morning.
Trending New

Test Grade Calculator

Calculate your test grade from any score. Supports US, UK, German, Pakistani, Indian, and Nigerian grading systems. Includes weighted grade calculator, reverse 'what score do I need?' tool, and a teacher class grader.

Convert any test score to a letter grade instantly.
Trending New

Tip Calculator & Bill Splitter

Calculate the perfect tip and split any restaurant bill between any number of people — equally or by custom amounts. Works in any currency worldwide with built-in tipping guides by country.

Split any bill fairly in seconds.
Trending

Today's Meal Timing Calculator

Get your personalised eating schedule based on your wake time and health goal. Science-backed circadian nutrition — the what matters far less than the when.

Exactly when should you eat today?
Trending New

What If I Invested Calculator

See exactly how much money you would have today if you had invested your daily, weekly, or monthly spending — on coffee, subscriptions, eating out, or any habit — instead of spending it.

What if you invested that money instead?
New

Net Worth Calculator

Free net worth calculator with fewer fields and a side-by-side layout that fits on one screen. Enter your assets and liabilities to instantly see your net worth, liquid net worth, and debt-to-asset ratio — calculated entirely in your browser.

Add up what you own, subtract what you owe, and see your real financial position.

All Calculators are 100% free • No registration required • Instant results