Free online calculators and converters
57 tools that do one thing each and do it immediately. No sign-up, no installation, and almost all of them run entirely in your browser.
- Percentage Calculator - Work out what X% of Y is, what percentage one number is of another, and percentage increase or decrease. Four calculators, instant answers, worked formulas.
- Grade Calculator - Work out your current weighted grade and exactly what score you need on the final exam to reach the grade you are aiming for.
- Fraction Calculator - Add, subtract, multiply and divide fractions with results reduced automatically, plus conversion between decimals, fractions and mixed numbers.
- Ratio Calculator - Solve a proportion for a missing value, simplify a ratio to lowest terms, or scale a recipe or mixture up and down while keeping the parts in balance.
- GPA Calculator - Calculate grade point average weighted by credit hours, on the 4.0 scale. Add your courses, see the GPA, and work out what you need next term.
- Tip Calculator - Calculate a tip at any percentage, split the total between any number of people, and round the per-person amount up or down to something payable.
- Discount Calculator - Find the sale price after one or more discounts, see how much you save, and work backwards from a sale price to the discount percentage.
- Aspect Ratio Calculator - Lock an aspect ratio and get the matching width or height. Includes 16:9, 4:3, 1:1, 21:9 and the common social and video presets.
- Loan Calculator - Calculate the monthly payment, total interest and payoff schedule for a mortgage, car loan or personal loan. See how extra payments shorten the term.
- Compound Interest Calculator - See how a lump sum and regular contributions grow with compound interest. Adjust the rate, term and compounding frequency and watch the breakdown.
- VAT & Sales Tax Calculator - Add VAT or sales tax to a net price, or strip it out of a gross price to find the net amount and the tax. Includes common European VAT rates.
- Rent vs Buy Calculator - Compare renting against buying over any horizon, including the investment return on the deposit you would not have tied up. Finds the break-even year.
- Debt Payoff Calculator - Plan your way out of multiple debts. Compare the avalanche and snowball methods side by side and see what an extra payment each month actually saves.
- Retirement Calculator - Project your savings to retirement and through it. See what the pot becomes, what income it sustains, and whether it runs out before you do.
- Car Loan Calculator - Calculate a car loan payment including trade-in, deposit and sales tax. See the total interest and how much of the price you are financing.
- Investment Return Calculator - Calculate compound annual growth rate and total return from a start and end value, and see how long a given rate takes to double your money.
- Profit Margin Calculator - Calculate profit margin and markup from cost and price, set a price from a target margin, and find the units needed to break even.
- Mortgage Affordability Calculator - Work out the mortgage a lender would actually offer you, from your income, debts and deposit, using the 28/36 debt-to-income rules lenders apply.
- Salary Calculator - Convert pay between hourly, daily, weekly, monthly and annual. Adjust hours and working weeks to compare a contract rate against a salary properly.
- Savings Calculator - Find out what regular monthly saving grows into, or how much you need to put aside each month to hit a target by a given date.
- Currency Converter - Convert between more than 150 currencies at current exchange rates. Swap direction in one click and see the rate used for the conversion.
- Elasticity Calculator - Calculate price elasticity of demand, income elasticity and cross elasticity using the midpoint method, with a plain reading of what each result means.
- P-Value Calculator - Calculate a p-value from a z-score or from an observed value, mean and standard deviation. Supports one- and two-tailed tests with an interpretation.
- Standard Deviation Calculator - Paste a list of numbers to get the mean, median, mode, range, variance and standard deviation, for both a sample and a whole population.
- Linear Regression Calculator - Fit a least-squares regression line to paired data. Get the slope, intercept, R-squared, correlation and a scatter plot with the fitted line.
- Chi-Square Calculator - Run a chi-square test on a contingency table or against expected frequencies. Get the statistic, degrees of freedom, p-value and an interpretation.
- BMI Calculator - Calculate body mass index from height and weight in metric or imperial units, see your category, and the weight range for a BMI of 18.5 to 25.
- Sleep Calculator - Find the bedtime or wake time that lets you finish a full sleep cycle, so you wake in light sleep rather than being pulled out of deep sleep.
- Calorie Calculator - Estimate your daily calorie needs from height, weight, age and activity, with targets for losing or gaining weight and a macronutrient breakdown.
- Body Fat Calculator - Estimate body fat percentage from height, neck, waist and hip measurements using the US Navy formula, with lean mass and category comparison.
- Running Pace Calculator - Calculate running pace, finish time or distance from any two of the three, with split times and predicted times at other race distances.
- Random Number Generator - Generate random numbers in any range, with or without duplicates. Draw one number or a whole set, using your browser's cryptographic randomness.
- Coin Flip - Flip a virtual coin once or many times. See heads and tails counts, the running percentage and the full sequence of results.
- Dice Roller - Roll any number of dice with any number of sides. Supports standard tabletop dice, modifiers and advantage or disadvantage on a d20.
- Wheel of Fortune - Enter a list of names or options and spin the wheel to pick one at random. Ideal for classroom picks, prize draws and settling group decisions.
- Time Duration Calculator - Work out the hours and minutes between two times, including shifts crossing midnight, with breaks deducted and decimal hours for payroll.
- Age Calculator - Calculate exact age from a date of birth in years, months and days, plus total weeks, days and hours lived and the countdown to the next birthday.
- Date Difference Calculator - Count the days, weeks, months and years between two dates, with an option to count business days only and to add or subtract days from a date.
- Unix Timestamp Converter - Convert a Unix timestamp to a human-readable date and back. Handles seconds and milliseconds, UTC and local time, and ISO 8601 output.
- Time Zone Converter - Convert a time between any number of time zones at once and find the hours that work for everyone, with daylight saving handled automatically.
- Unit Converter - Convert length, weight, temperature, area, volume, speed, time and digital storage between metric and imperial units with full precision.
- Cooking Converter - Convert cups, spoons, grams, ounces and millilitres for real ingredients. Flour and honey weigh very differently per cup, and this accounts for that.
- Roman Numeral Converter - Convert numbers to Roman numerals and Roman numerals to numbers, from 1 to 3999, with a breakdown showing how each numeral is built.
- Color Converter - Convert colors between HEX, RGB, HSL, HSV and CSS names. Includes a live preview, contrast checking and shade and tint generation.
- Word & Character Counter - Count words, characters with and without spaces, sentences and paragraphs, estimate reading time, and transform text case as you type.
- Text Compare - Compare two texts side by side and see exactly which lines were added, removed or changed, with the option to ignore case and whitespace.
- Lorem Ipsum Generator - Generate lorem ipsum placeholder text by paragraphs, sentences, words or characters, as plain text or wrapped in HTML tags.
- Base64 Encoder / Decoder - Encode text to Base64 and decode Base64 back to text, with full Unicode support and a URL-safe variant. Runs entirely in your browser.
- URL Encoder / Decoder - Percent-encode and decode URLs and query strings, with separate handling for full URLs and individual components. Includes a query string parser.
- JSON Formatter - Format, validate and minify JSON with clear error messages that point at the line and column. Sort keys and escape or unescape strings.
- UUID Generator - Generate cryptographically random version 4 UUIDs, one or thousands at a time, in uppercase, lowercase, braced or plain formats.
- Hash Generator - Generate SHA-1, SHA-256, SHA-384 and SHA-512 hashes of any text using the Web Crypto API. Runs locally, nothing is uploaded.
- Password Generator - Generate strong random passwords or memorable passphrases with adjustable length and character sets, plus an entropy-based strength estimate.
- JWT Decoder - Decode a JSON Web Token to read its header, claims and expiry. Runs entirely in your browser, so tokens are never transmitted.
- Regex Tester - Test a regular expression against sample text with live highlighting, capture groups, named groups and a plain-language explanation of errors.
- Number Base Converter - Convert numbers between binary, octal, decimal, hexadecimal and any base from 2 to 36, with the bit pattern shown alongside the result.
- What's My IP - See your public IP address along with its approximate location, internet provider and the details your browser reveals to every site you visit.
Swiss municipal tax comparison
A German-language section comparing what each municipality levies in
5 Swiss cantons — 458 municipalities, one page each, with the
part of the tax bill that actually depends on your address rather than the headline rate the cantons
publish. The reconciled dataset behind it is published as CSV and JSON.
Cantons covered: Zürich (160), Basel-Landschaft (86), Freiburg (121), Thurgau (80), Zug (11).