Free online tools & calculators
Use once, no app needed. 121 fast, private utilities that run entirely in your browser — nothing to install, no account required.
Fast converters for length, weight, volume, temperature, speed, data and more. Enter a value, pick your units, and get the conversion live as you type.
Length Converter
Convert mm, cm, m, km, inches, feet, yards and miles instantly.
Weight Converter
Convert kg, g, mg, ounces, pounds, stone and tonnes instantly.
Temperature Converter
Celsius, Fahrenheit, Kelvin and Rankine converted as you type.
Volume Converter
Convert liters, ml, gallons, cups, pints, fl oz and more.
Area Converter
Convert m², km², acres, hectares, ft² and more.
Speed Converter
Convert km/h, mph, m/s, knots and ft/s.
Data Size Converter
Convert bytes, KB, MB, GB, TB — decimal and binary.
Fuel Economy Converter
Convert L/100km, km/L, US mpg and UK mpg.
Pressure Converter
Pa, bar, psi, atm, mmHg and inHg converted as you type.
Energy Converter
J, kJ, calories, Wh, kWh, BTU and more, converted instantly.
Power Converter
Watts, horsepower (both kinds), BTU/h and foot-pounds/s.
Angle Converter
Degrees, radians, gradians, turns and arc units.
Frequency Converter
Hz to GHz, rpm and beats per minute, converted live.
Time Converter
Milliseconds to years, instantly, with average-month years.
Everyday money calculators for interest, loans, tips, taxes and spending. No sign-up, no ads-only clutter — enter your numbers and get an answer instantly.
Tip Calculator
Work out the tip and split the bill between friends in seconds.
Discount Calculator
See the final price after a percent-off discount — or find the percentage saved.
Sales Tax Calculator
Add tax to a price, or remove it from a tax-inclusive price.
Simple Interest Calculator
Interest = principal × rate × time, computed instantly.
Compound Interest Calculator
See savings growth with compounding, optional regular contributions.
Loan Payment Calculator
Monthly payment, total interest and payoff total for any loan.
Mortgage Calculator
Estimate monthly mortgage payments including down payment impact.
Fuel Cost Calculator
Trip fuel cost from distance, efficiency and fuel price.
Hourly to Salary Calculator
Annualize an hourly wage into salary terms.
Salary to Hourly Calculator
What an annual salary is actually worth per hour.
Profit Margin Calculator
Margin and markup from revenue and cost, both shown.
Markup Calculator
Cost plus markup percent to price — and the margin it implies.
ROI Calculator
Return on investment, total and annualized.
Break-Even Calculator
Units and revenue needed to cover fixed costs.
Savings Goal Calculator
When you reach the goal — and the monthly deposit that gets you there.
Inflation Calculator
See how inflation changes the value of money over time.
Credit Card Payoff Calculator
See how long it takes to pay off a credit card balance.
Currency Converter
Convert between major currencies with approximate rates.
Work out ages, date differences, deadlines and durations in seconds. Timezone-free by design: everything runs in your browser.
Age Calculator
Exact age in years, months, days — plus days lived until a date.
Date Difference Calculator
Days, weeks, months and years between any two dates.
Add or Subtract Days
Add or subtract days, weeks, months or years from a date.
Countdown Timer
Count down hours, minutes and seconds with an alarm beep.
Stopwatch
Precise stopwatch with laps and hundredths of a second.
Date to Unix Timestamp Converter
Turn any date and time into Unix seconds and milliseconds.
Timestamp to Date Converter
Decode Unix timestamps into readable local and UTC times.
Business Days Calculator
Count working days between dates, with a custom work week.
Week Number Calculator
ISO week number, week-year and week range for any date.
Time Zone Converter
Convert times between IANA time zones, DST-accurate.
One-click generators for passwords, IDs, QR codes, hashes and randomness. Everything is generated locally in your browser — nothing is sent to a server.
Password Generator
Strong random passwords — length, symbols and ambiguity options.
Random Number Generator
Random integers in any range, with optional duplicates allowed.
Coin Flip
Flip one or many virtual coins and count heads vs tails.
Dice Roller
Roll any number of dice with any number of sides.
UUID Generator
Generate v4 UUIDs in bulk with one-click copy.
QR Code Generator
Make QR codes from links or text and download as PNG.
Hash Generator
SHA-1, SHA-256, SHA-384 and SHA-512 hashes of any text.
Hash Verifier
Check text against an expected SHA hash — the valid “reverse” of hashing.
Hash to Text Decoder
Identify the hash algorithm and bit length from any digest, so you know exactly what you are looking at.
Password Strength Checker
Entropy, crack-time estimate and plain-English advice.
Wheel Spinner
Spin a custom prize or decision wheel for one fair pick.
Yes or No Decider
A fair crypto-random 50/50 answer, with history.
PIN Generator
Uniform random numeric PINs in bulk, 4–12 digits.
MAC Address Generator
Random MACs with correct local, unicast and multicast flag bits.
Random Color Generator
Random, harmonious, pastel or dark colors with formats.
Lottery Number Generator
Quick picks for any game shape — 6/49 and friends.
QR Code Reader
Read a QR image back to its payload and detect its type.
Passphrase Generator
Generate memorable, high-entropy passphrases.
Clean, count and transform text without an account or an app. Paste, tweak, copy the result — done.
Word Counter
Words, characters, sentences, paragraphs and reading time.
Case Converter
Switch text between UPPER, lower, Title, Sentence and camelCase.
Line Sorter
Sort lines A→Z, Z→A, by length, or shuffle them.
Remove Duplicate Lines
Strip repeated lines, optionally ignoring case and trimming space.
Whitespace Cleaner
Trim line ends, collapse spaces and remove empty lines.
Find & Replace
Replace every occurrence, optionally with regex support.
Lorem Ipsum Generator
Classic filler text by paragraphs, sentences or words.
Text Reverser
Flip characters, words or lines — or mirror each word.
Text to Binary Converter
Encode any text to UTF-8 binary bytes.
Binary to Text Converter
Decode 8-bit binary back into readable text.
Text to Morse Code Converter
Translate text to International Morse code, with playback.
Morse Code to Text Converter
Decode Morse back to text, tolerant of spacing styles.
Number to Words Converter
Spell numbers out in English, cheques and contracts ready.
Words to Number Converter
Parse English number words back into digits.
Number to Roman Numeral Converter
Write numbers as Roman numerals, including large values.
Roman Numeral to Number Converter
Parse Roman numerals, even non-standard ones like IIII.
Text Diff Checker
Compare two texts line by line and see exactly what changed.
Text to Hex Converter
Show the hexadecimal bytes behind any text.
Hex to Text Converter
Turn hexadecimal bytes back into readable text.
Everyday calculators for percentages, grades, health numbers and the small sums that come up around the house.
Calories Burned Calculator
kcal burned per session and per week, from MET tables.
Water Intake Calculator
Personal daily water target in liters and glasses.
Ideal Weight Calculator
Four classic formulas and the healthy-BMI range compared.
Body Fat Percentage Calculator
US Navy tape method: body fat, fat and lean mass.
Due Date Calculator
Estimated due date from LMP with cycle adjustment.
Bedtime & Sleep Cycle Calculator
Work back from your alarm in 90-minute sleep cycles.
BMI Calculator
Body Mass Index from height and weight, with category.
BMR & Calorie Calculator
Basal metabolic rate and daily calories by activity level.
Percentage Calculator
X% of a number, percent change, and “what percent is X of Y”.
Grade Calculator
Weighted final grade from assignments, plus what score you need.
GPA Calculator
Unweighted 4.0-scale GPA from course grades and credits.
Aspect Ratio Calculator
Resize width or height while keeping aspect ratio.
Unit Price Comparison
Which package is cheaper per unit? Compare two sizes.
Split the Bill
Divide any amount between people, with optional tip rounding.
Percentage Change Calculator
Calculate the percent increase or decrease between two numbers.
TDEE Calculator
Estimate daily calorie needs from age, size, and activity.
Ratio Calculator
Simplify a ratio and see its decimal form.
Pace Calculator
Running or walking pace from distance and time.
Small utilities developers use once and need right now: encoders, formatters and color math that run entirely client-side.
Base64 Encoder / Decoder
Encode text to Base64 or decode it back, URL-safe optional.
URL Encoder / Decoder
Percent-encode or decode URLs and query parameters.
JSON Formatter & Validator
Pretty-print or minify JSON and pinpoint syntax errors.
Color Converter
Convert HEX, RGB and HSL both ways, with a live swatch.
HTML Entity Encoder
Escape (or unescape) & < > " ' for safe HTML.
Decimal to Binary Converter
Convert decimal numbers to binary, with hex and octal alongside.
Binary to Decimal Converter
Turn 0s and 1s back into a decimal number, validated as you type.
Decimal to Hexadecimal Converter
Convert base-10 numbers to hex with prefix and case options.
Hexadecimal to Decimal Converter
Decode hex values (0x optional) back to decimal and binary.
URL Slug Generator
Turn any title into a clean, URL-safe slug.
CSV to JSON Converter
Convert spreadsheets to JSON arrays, quotes and all.
JSON to CSV Converter
Flatten JSON arrays into rows for spreadsheets.
Markdown to HTML Converter
Render Markdown and copy the generated HTML.
HTML to Markdown Converter
Turn HTML markup into clean Markdown.
JWT Decoder
Decode a JSON Web Token’s header and payload locally.
Regex Tester
Test regular expressions live with matches and replace preview.
JWT Encoder
Build and HMAC-sign a JSON Web Token in the browser.
JSON to XML Converter
Turn JSON into indented XML, with arrays as repeated elements.
XML to JSON Converter
Convert XML into JSON, collapsing repeated elements into arrays.
YAML to JSON Converter
Parse YAML into JSON, including nested maps and lists.
JSON to YAML Converter
Render JSON as clean, human-readable YAML.
Cron Expression Parser
Explain a cron expression in plain English and list its next runs.
Unix Permission Calculator
Convert chmod modes between octal, symbolic and rwx notation.
Color Contrast Checker
WCAG 2.1 contrast ratio for any two colors, with AA and AAA verdicts.
No tools match that search. Try a shorter term — or tell us what you need on the about page.