Quick Tools for Everyday Questions
Stop Googling formulas - just get the answer, free and instant.
Sleep Cycle
Find your perfect bedtime or wake-up based on 90-min cycles.
Tip Calculator
Split the bill and calculate tips instantly across any group size.
Percentage Calculator
4 modes: find %, change, add/subtract. Instant results with formula shown.
Countdown Calculator
Days, weeks, months until any date. Quick picks for holidays included.
Word Counter
Count words, characters, sentences & paragraphs. Keyword density + reading time.
Time Zone Converter
Compare up to 5 cities. Business hours highlighted. DST-aware.
Coin Flip & Dice Roller
Flip coins, roll any dice (d4-d20), track tallies and roll history.
BMI Calculator
Metric & imperial. Colour-coded gauge, healthy weight range, and category breakdown.
Random Number Generator
Single or multi numbers, no-repeat mode, dice shortcuts, lottery mode, and history.
Reading Time Estimator
Paste any text and get reading, speaking & audiobook times. Adjustable speed slider.
Age Calculator
Exact age in years, months & days. Total days, weeks, hours lived, star sign & more.
Calorie Calculator
Find your daily calorie needs to maintain, lose or gain weight. Metric & imperial.
Password & Passphrase Generator
Cryptographically secure passwords and memorable passphrases with strength meter & bulk mode.
GPA Calculator
Simple & cumulative GPA. US & UK systems, reverse calculator, degree classifications.
Fuel Cost Calculator
Plan road trips: total cost, cost per person, CO₂ emissions & compare two cars.
Unit Converter
Length, weight, temperature, volume, speed, area & time. Instant results with formula shown.
Clothing Size Converter
Convert clothing & shoe sizes across US, UK, EU, FR, IT, AU, JP and more.
Currency Converter
Convert 58 currencies instantly. Quick pairs, multi-currency table, and rate context.
Loan Repayment Calculator
Monthly repayments, total interest, amortisation schedule, and loan comparison.
Cycle & Ovulation Tracker
Track your cycle, fertile window and ovulation day with a visual monthly calendar.
Free Online Calculators for Everyday Life
CalcWiz brings together 20+ free, instant calculators and conversion tools in one place. Whether you are splitting a restaurant bill, checking your BMI, planning a loan repayment, converting currencies for a trip, or generating a secure password, every tool on this site runs entirely in your browser - no sign-up, no downloads, and no data sent to a server.
Unlike ad-heavy calculator sites that bury the answer behind pop-ups and sign-up walls, CalcWiz is built to give you the answer immediately. Each tool includes the formula or method used, so you can verify the result and understand how it was calculated. Our calculators cover finance (tip, loan, currency, fuel cost), health (BMI, calorie, ovulation), time and dates (sleep cycles, countdown, age, time zones), writing (word counter, reading time), academic (GPA), and everyday utilities (unit converter, clothing sizes, password generator, percentage, and more).
All tools are free to use, work on mobile and desktop, and require no account. New calculators are added regularly - if there is a tool you would like to see, let us know.
📚 In-Depth Guides
Beyond quick calculations, we publish original long-form articles exploring the science, history, and mathematics behind our tools - from the neuroscience of sleep cycles to the economics of tipping culture.
Browse Guides →✨ All calculations are estimates. Consult a professional for medical advice.
