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.
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.
Binary ↔ Hexadecimal Converter
Easily convert numbers between binary (base 2) and hexadecimal (base 16) systems. Essential for programmers, web developers, and computer science students.
Binary ↔ Octal Converter
Easily convert numbers between binary (base 2) and octal (base 8) systems. Useful for computing and digital electronics.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
Electricity Bill Calculator
Find out exactly how much each appliance costs you per day, month, and year. Finally understand your electricity bill.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
All Calculators are 100% free • No registration required • Instant results
Browse All Tools by Category
12 categories — find exactly what you need
Health & Wellness
Free health calculators for BMI, sleep cycles, hydration,...
4 tools
Education & Learning
Free calculators for students and teachers — grades, test...
1 tools
Finance & Money
Free financial calculators for loans, compound interest, ...
11 tools
Time & Date
Free time calculators for age, countdowns, deadlines, dat...
3 tools
Math & Statistics
Free calculators for percentages, averages, probability, ...
0 tools
Science
Free calculators for physics, chemistry, biology, and sci...
0 tools
Engineering & Construction
Free calculators for area, volume, materials, concrete, a...
0 tools
Food & Nutrition
Free nutrition calculators for meal timing, calories, mac...
1 tools
Digital & Technology
Free calculators for number system conversion, screen tim...
6 tools
Sports & Fitness
Free fitness calculators for training, performance, pace,...
0 tools
Everyday Life
Free calculators for daily habits, productivity, life pla...
2 tools
Space & Universe
Free cosmic calculators for your age on other planets, li...
1 tools
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