All tools
110 tools across 8 categories. Press to search from anywhere.
Calculators
Everyday maths, answered instantly
Calculators
Percentage Calculator
Work out percentages, percentage change and reverse percentages.
Basic Calculator
A plain calculator with a running history of what you typed.
Scientific Calculator
Trigonometry, logarithms, powers and roots with degrees or radians.
Percentage Increase Calculator
Add a percentage to a number and see the amount added.
Percentage Decrease Calculator
Subtract a percentage from a number and see what remains.
Percentage Difference Calculator
Compare two numbers where neither is the starting point.
Fraction Calculator
Add, subtract, multiply and divide fractions, simplified.
Ratio Calculator
Simplify ratios, solve proportions and split a total.
Average Calculator
Mean, median, mode and range from a list of numbers.
Discount Calculator
Work out a sale price and how much you actually save.
Tip Calculator
Work out a tip and split the bill between people.
Finance
Loans, interest and returns
Finance
EMI Calculator
Monthly repayment, total interest and a full amortisation schedule.
Loan Calculator
Repayments, total interest and a full amortisation schedule.
Simple Interest Calculator
Interest on the original amount only, with no compounding.
Compound Interest Calculator
Growth with interest on interest, plus regular contributions.
Investment Calculator
Project an investment with contributions and see the real return.
SIP Calculator
Project a monthly systematic investment plan.
Sales Tax Calculator
Add or remove sales tax, VAT or GST from a price.
Salary Calculator
Convert pay between hourly, daily, weekly, monthly and yearly.
Profit Margin Calculator
Margin, markup and profit from cost and selling price.
ROI Calculator
Return on investment, with the annualised rate.
Break-Even Calculator
How many units you must sell to cover your costs.
Converters
Any unit to any other unit
Converters
Kilogram to Pound Converter
Convert kilogram to pound — kg to lbs with a reference table.
Pound to Kilogram Converter
Convert pound to kilogram — lbs to kg with a reference table.
Celsius to Fahrenheit Converter
Convert celsius to fahrenheit — celsius to fahrenheit with a reference table.
Fahrenheit to Celsius Converter
Convert fahrenheit to celsius — fahrenheit to celsius with a reference table.
Centimetre to Inch Converter
Convert centimetre to inch — cm to inches with a reference table.
Inch to Centimetre Converter
Convert inch to centimetre — inches to cm with a reference table.
Kilometre to Mile Converter
Convert kilometre to mile — km to miles with a reference table.
Mile to Kilometre Converter
Convert mile to kilometre — miles to km with a reference table.
Foot to Metre Converter
Convert foot to metre — feet to meters with a reference table.
Megabyte (1000²) to Gigabyte (1000³) Converter
Convert megabyte (1000²) to gigabyte (1000³) — mb to gb with a reference table.
Litre to Gallon (US) Converter
Convert litre to gallon (us) — liters to gallons with a reference table.
Cup (US) to Millilitre Converter
Convert cup (us) to millilitre — cups to ml with a reference table.
Length Converter
Convert between metres, feet, inches, miles and more.
Weight Converter
Convert kilograms, pounds, ounces, stones and tonnes.
Temperature Converter
Convert Celsius, Fahrenheit, Kelvin and Rankine.
Volume Converter
Convert litres, gallons, cups, pints and fluid ounces.
Speed Converter
Convert km/h, mph, knots, m/s and Mach.
Area Converter
Convert square metres, square feet, acres and hectares.
Data Storage Converter
Convert bytes, KB, MB, GB, TB — and KiB vs KB.
Pressure Converter
Convert bar, psi, pascals, atmospheres and mmHg.
Energy Converter
Convert joules, calories, kWh, BTU and electronvolts.
Power Converter
Convert watts, kilowatts, horsepower and BTU/h.
Frequency Converter
Convert hertz, kilohertz, megahertz, gigahertz and rpm.
Cooking Converter
Convert cups, tablespoons, teaspoons and millilitres.
Fuel Economy Converter
Convert mpg, km/l and litres per 100 km.
Angle Converter
Convert degrees, radians, gradians and turns.
Force Converter
Convert newtons, kilogram-force, pound-force and dynes.
Time Unit Converter
Convert seconds, minutes, hours, days, weeks and years.
Date & Time
Dates, durations and time zones
Date & Time
Age Calculator
Your exact age in years, months and days — plus the next birthday.
Date Difference Calculator
Time between two dates in years, months, weeks and days.
Days Between Dates
The number of days from one date to another.
Add or Subtract Days
Find the date a number of days, weeks or months away.
Business Days Calculator
Count working days between dates, skipping weekends and holidays.
Time Duration Calculator
Time between two times, and add or subtract durations.
Unix Timestamp Converter
Convert Unix timestamps to dates and back.
Time Zone Converter
Convert a time between any two time zones.
World Clock
Current time in cities around the world, side by side.
Stopwatch
Start, stop and record laps, accurate to hundredths.
Timer
Count down from any duration, with an alert at zero.
Countdown Timer
Count down to a specific date and time.
Developer
Encode, format, generate, inspect
Developer
JSON Formatter
Format, validate and minify JSON — with the error line and column.
JSON Minifier
Strip every unnecessary byte from JSON.
JSON Validator
Check JSON is valid and find the exact line of any error.
Base64 Encoder
Encode text to Base64, with a URL-safe option.
Base64 Decoder
Decode Base64 back to text, standard or URL-safe.
URL Encoder
Percent-encode text so it survives inside a URL.
URL Decoder
Turn percent-encoded text back into readable characters.
HTML Entity Encoder
Escape HTML so it displays as text instead of markup.
HTML Entity Decoder
Turn & < and é back into readable characters.
UUID Generator
Generate UUID v4, ULID or Nano ID in bulk.
Password Generator
Strong random passwords with a real strength estimate.
Hash Generator
SHA-1, SHA-256, SHA-384, SHA-512 and CRC32 at once.
Regex Tester
Test a regular expression and see every match and group.
JWT Decoder
Read a JSON Web Token's header, payload and expiry.
Color Converter
Convert between HEX, RGB, HSL, HSV and CMYK, with contrast checks.
Lorem Ipsum Generator
Placeholder text by paragraph, sentence or word.
URL Parser
Break a URL into its protocol, host, path and parameters.
Text
Count, clean and reshape text
Text
Word Counter
Count words, characters, sentences and paragraphs as you type.
Character Counter
Count characters with and without spaces, against any limit.
Reading Time Calculator
How long a piece takes to read silently or aloud.
Case Converter
Convert text between eleven cases, including camelCase and snake_case.
Remove Duplicate Lines
Strip repeated lines from a list, keeping the first of each.
Text Sorter
Sort lines alphabetically, numerically, by length, or shuffle them.
Whitespace Cleaner
Collapse extra spaces, trim lines and remove blank lines.
Slug Generator
Turn any title into a clean, URL-safe slug.
Text Reverser
Reverse text by character, by word or by line.
Word Frequency Counter
See which words appear most often, ranked with a bar chart.
Student
Grades, marks and coursework maths
Student
GPA Calculator
Credit-weighted grade point average across your courses.
CGPA Calculator
Combine several semesters into one cumulative GPA.
Marks Percentage Calculator
Turn marks across subjects into an overall percentage.
Attendance Calculator
Your attendance percentage, and how many classes you can still miss.
Grade Calculator
Your weighted grade so far, from assignments and exams.
Final Grade Calculator
What you need on the final exam to hit your target grade.
Quadratic Equation Solver
Solve ax² + bx + c = 0, with the working shown.
Matrix Calculator
Add, subtract, multiply, transpose, invert and find determinants.
Statistics Calculator
Mean, median, mode, standard deviation and quartiles at once.
Probability Calculator
Combinations, permutations, binomial and normal probabilities.
Engineering
Circuits, signals and components
Engineering
Ohm's Law Calculator
Solve voltage, current, resistance and power from any two.
Resistor Color Code Calculator
Decode 3, 4, 5 and 6-band resistors to a resistance and tolerance.
Series Resistance Calculator
Add resistors in series and see the total.
Parallel Resistance Calculator
Combine resistors in parallel into one equivalent value.
LED Resistor Calculator
Size the series resistor an LED needs on your supply.
Voltage Divider Calculator
Work out the output voltage of a two-resistor divider.
RC Time Constant Calculator
Time constant, cutoff frequency and charge curve for an RC circuit.
LC Resonant Frequency Calculator
Resonant frequency of an inductor and capacitor.
Decibel Calculator
Convert between ratios and decibels for power or voltage.
Wavelength Calculator
Convert between frequency and wavelength, with antenna lengths.
Metric Prefix Converter
Convert between pico, nano, micro, milli, kilo, mega and giga.