Every calculation, done in a second.
Loans, BMI, unit conversions, dates and text tools in one place, updating as you type.
Popular tools
Start with the most-used calculators
Loan Calculator
Monthly payment, total interest
CalculatorsBMI Calculator
Body mass index & healthy weight
HealthUnit Converter
Length, weight, temperature
ConvertersPercentage Calculator
Ratios, increase/decrease
CalculatorsTip Calculator
Tip amount, total, per person
CalculatorsDiscount Calculator
Final price & amount saved
CalculatorsAge Calculator
Age in years, months, days
Date & TimePassword Generator
Random secure passwords, strength check
DeveloperScientific Calculator
Trig, log, sqrt, powers and more
CalculatorsCalorie Calculator
BMR and daily calorie needs (TDEE)
HealthCompound Interest Calculator
Final balance, total interest, contributions
CalculatorsCase Converter
UPPER, lower, Title, Sentence case
OfficeBase64 Encoder/Decoder
Encode or decode Base64 text instantly
DeveloperColor Converter
HEX to RGB and HSL with color preview
DeveloperGPA Calculator
Weighted GPA from course grades and credits
StudyData Storage Converter
Convert between Bit, Byte, KB, MB, GB, TB, PB
ConvertersTime Converter
Convert between ms, s, min, h, day, week, month, year
ConvertersNumber Base Converter
Convert between binary, octal, decimal, hex
DeveloperAspect Ratio Calculator
Find missing width or height while keeping the aspect ratio
DeveloperRandom Number Generator
Generate random integers with min, max, count, unique
Brain & GamesLorem Ipsum Generator
Generate placeholder paragraphs, sentences or words
OfficeMorse Code Translator
Translate text to Morse code and back
LanguageRoman Numeral Converter
Convert between Arabic numbers and Roman numerals
LanguageNATO Phonetic Alphabet
Spell any text using NATO phonetic words
LanguageBPM Counter
Tap to measure beats per minute
MusicNote Frequency Calculator
Frequency in Hz for any musical note and octave
MusicAverage Calculator
Mean, median, min, max, sum from a list of numbers
CalculatorsTemperature Converter
Celsius, Fahrenheit and Kelvin — live conversion
ConvertersHash Generator
SHA-1, SHA-256, SHA-384, SHA-512 from any text
DeveloperUUID Generator
Generate v4 UUIDs one at a time or in bulk
DeveloperUnix Timestamp Converter
Timestamp to date/time and back, UTC and local
DeveloperJSON Formatter
Beautify, minify and validate JSON in one click
DeveloperURL Encoder / Decoder
Encode or decode URL components instantly
DeveloperWord Counter
Words, characters, sentences, paragraphs, reading time
OfficeSales Tax Calculator
Tax amount, total price, and reverse (total to net)
CalculatorsDice Roller
Roll d4/d6/d8/d10/d12/d20/d100, up to 10 dice
Brain & GamesCoin Flip
Flip a coin, track heads vs tails tally
Brain & GamesCharacter Counter
Characters, words, lines and UTF-8 bytes
OfficeDays Until Calculator
Days until a date or between two dates
Date & TimeFancy Text Generator
Decorative fonts, text emoticons, symbols and ASCII art
OfficeQR Code Generator
Text or URL to a QR code, download as PNG
OfficeSpin the Wheel
Spin a wheel to pick a random name or item
Brain & GamesReaction Time Test
Measure your click reaction speed in milliseconds
Brain & GamesText to Speech
Read any text aloud with adjustable voice, speed, pitch
OfficeFortune Cookie Generator
Crack open a cookie for a random saying
Brain & GamesWhy use utilduck
Completely free
Every tool is free with no registration.
Private by design
Calculations run in your browser; input is not sent to a server.
Instant results
Real-time calculation as you type.
Mobile friendly
Works cleanly on phones, tablets, and desktops.
Accurate formulas
Standard formulas with the reasoning explained.
Educational
Understand the math behind each result.
All calculators provide estimates for reference only. Actual results may vary. Consult a professional before important decisions.