All tools

Browse all free ToolKivo calculators, converters, random tools, timers, tests, and text utilities in one place.

• Percentage Calculator

  Calculate X% of a number, what percent one value is of another, and the percentage change between an old and a new value.

• Discount Calculator

  Find the saving and final price from an original price and a percentage discount, including stacked offers applied one after another.

• Age Calculator

  Calculate age in completed years on any date, with the total days lived and the days remaining until the next birthday.

• Date Difference Calculator

  Count the exact days between two dates, with the gap also shown in weeks and approximate months, including leap years and past dates.

• Time Duration Calculator

  Calculate the elapsed hours and minutes between two clock times, including overnight spans that finish after midnight.

• BMI Calculator

  Calculate adult body mass index from weight and height in metric or imperial units, with the matching adult reference category.

• Tip Calculator

  Calculate a tip from the bill and a percentage, then see the total and an even per-person share for any group size.

• Loan Calculator

  Estimate the fixed monthly payment, total repaid and total interest for a loan from the amount, annual interest rate and term.

• Compound Interest Calculator

  Project the future value of savings with compound interest and regular contributions, separating the money you put in from the growth.

• Fuel Cost Calculator

  Estimate the fuel a trip needs and what it costs, from the distance, the efficiency in L/100 km, km/L or US MPG, and the price per liter.

• Length Converter

  Convert between millimeters, centimeters, meters, kilometers, inches, feet, yards and miles using exact international factors.

• Weight Converter

  Convert between milligrams, grams, kilograms, ounces, pounds and stones using exact international mass factors.

• Temperature Converter

  Convert temperatures between Celsius, Fahrenheit and Kelvin, including oven settings, body temperature and scientific values.

• Area Converter

  Convert between square meters, square kilometers, square feet, acres and hectares using exact area factors.

• Volume Converter

  Convert between milliliters, liters, cubic meters, fluid ounces, cups, pints and gallons using US customary definitions.

• Speed Converter

  Convert speeds between kilometers per hour, miles per hour, meters per second and knots.

• Data Storage Converter

  Convert between decimal and binary storage units: bytes, KB, MB, GB, TB and their KiB, MiB, GiB, TiB counterparts.

• Cooking Converter

  Convert kitchen measures by volume: teaspoons, tablespoons, cups, milliliters and liters, using US customary sizes.

• Wheel Spinner

  Spin a wheel to pick one item fairly from a list you type, one option per line.

• Random Name Picker

  Pick one or more random names from a pasted list, drawn without replacement.

• Random Number Generator

  Generate random whole numbers in a range you choose, in any quantity, with or without duplicates.

• Coin Flip

  Flip a virtual coin once or run thousands of flips at a time and see the running totals.

• Random Team Generator

  Shuffle a list of names into random teams whose sizes never differ by more than one person.

• Online Timer

  Run a countdown timer in your browser with an alert at zero and an optional repeat.

• Online Stopwatch

  Time anything in your browser with start, pause, resume, reset and a list of lap times.

• Pomodoro Timer

  Alternate focus sessions with short breaks and take a longer break after every fourth session.

• Countdown Timer

  See how much time is left until a date and time you choose, updated continuously.

• Typing Speed Test

  Measure your typing speed in words per minute, with accuracy and character counts.

• Reaction Time Test

  Measure your reaction time over several attempts and take the median as your score.

• Click Speed Test

  Measure how many times you can click per second over a duration you choose.

• Average Calculator

  Find the average, sum, count, minimum and maximum of a list of numbers pasted in any common layout.

• Ratio Calculator

  Simplify a ratio to its smallest whole numbers, including ratios with decimals or a zero part, and check equivalent ratios.

• Fraction Calculator

  Add, subtract, multiply or divide two fractions and see the result reduced to lowest terms with its decimal value.

• Sales Tax Calculator

  Calculate sales tax and the final price from a pre-tax amount and any combined tax rate, in any currency.

• Profit Margin Calculator

  Calculate profit, profit margin and markup from the cost and the selling price, including losses when the cost is higher.

• Grade Calculator

  Turn points earned and points possible into a percentage grade, with a letter grade on a simple 90/80/70/60 scale.

• Running Pace Calculator

  Calculate running pace per kilometer or mile and average speed from a distance and an elapsed time.

• Work Hours Calculator

  Calculate worked time between a clock-in and a clock-out after subtracting an unpaid break, in hours and minutes and in decimal hours.

• Area and Square Footage Calculator

  Calculate the area of a rectangular space in square feet or square meters, with the result shown in both units.

• Unit Price Calculator

  Compare packages by calculating the price per item, per kilogram or per any unit you choose.

• Pressure Converter

  Convert pressure between pascals, kilopascals, bars, PSI, atmospheres and millimeters of mercury.

• Energy Converter

  Convert energy between joules, calories, watt-hours, kilowatt-hours and British thermal units.

• Power Converter

  Convert power between watts, kilowatts, megawatts and mechanical horsepower.

• Force Converter

  Convert force between newtons, kilonewtons, pound-force and kilogram-force.

• Angle Converter

  Convert angles between degrees, radians, gradians and turns for maths, code and drawings.

• Time Unit Converter

  Convert time between milliseconds, seconds, minutes, hours, days, weeks and years with fixed factors.

• Dice Roller

  Roll one or more virtual dice with any number of sides and see each die and the total.

• Password Generator

  Generate a strong random password in your browser, choosing the length and which character sets to include.

• List Shuffler

  Shuffle a pasted list so every item appears exactly once in a random order.

• Word Counter

  Count words, characters, sentences and lines as you type, with a reading-time estimate.

• Character Counter

  Count characters with and without spaces as you type, along with words, sentences and lines.

• Case Converter

  Convert text to uppercase, lowercase, title case or sentence case without touching punctuation or spacing.

• Duplicate Line Remover

  Remove repeated lines from a pasted list while keeping the first occurrence in its original position.

• Sort Lines

  Sort pasted lines alphabetically in ascending or descending order, with natural number ordering.

• Whitespace Remover

  Trim every line, collapse runs of spaces and tabs into one space, and optionally drop blank lines.

• Median Calculator

  Find the median of a list of numbers, with the middle values used and the count, for data that contains outliers.

• Mode Calculator

  Find the most frequent value or values in a list of numbers, with the highest frequency and the count.

• Standard Deviation Calculator

  Calculate the population and sample standard deviation of a list of numbers, together with the mean and the count.

• Fraction to Decimal Calculator

  Convert a fraction into a decimal and a percentage by dividing the numerator by the denominator.

• Decimal to Fraction Calculator

  Convert a decimal into a simplified fraction, with a maximum denominator you choose for exact values or close approximations.

• GCD and LCM Calculator

  Find the greatest common divisor and the least common multiple of two or more whole numbers.

• Prime Number Checker

  Check whether a whole number is prime, and see its smallest divisor when it is not.

• Quadratic Formula Calculator

  Solve ax² + bx + c = 0 with the quadratic formula, including repeated roots and complex conjugate pairs.

• Pythagorean Theorem Calculator

  Find a missing side of a right triangle with a² + b² = c², choosing whether to calculate the hypotenuse or a leg.

• Circle Calculator

  Calculate the diameter, circumference and area of a circle from its radius, with full precision for π.

• Triangle Area Calculator

  Calculate the area of a triangle from a base and perpendicular height, or from three known sides with Heron’s formula.

• Probability Calculator

  Turn favorable and total outcomes into a probability, a percentage and the odds for the event.

• Combinations and Permutations Calculator

  Count how many ways r items can be chosen from n, as combinations when order does not matter and permutations when it does.

• Simple Interest Calculator

  Calculate simple interest and the final amount from a principal, an annual rate and a time in years, with no compounding.

• Savings Goal Calculator

  Estimate how many months of monthly saving and interest it takes to reach a savings target, and the balance when you get there.

• ROI Calculator

  Calculate the gain or loss on an investment and the return on investment as a percentage of what you put in.

• Break-Even Calculator

  Work out how many units you need to sell to cover fixed and variable costs, and the revenue that volume brings in.

• Fuel Economy Converter

  Convert fuel economy between L/100 km, km/L, US MPG and imperial MPG, in the right direction each time.

• Reverse Text

  Reverse text by characters or reverse the order of the words, entirely inside your browser.

• Find and Replace Text

  Replace every occurrence of a phrase with another, with optional case-sensitive matching.

• Salary Calculator

  Turn an hourly wage into weekly, monthly and annual gross pay, with paid weeks and part-time hours taken into account.

• Overtime Pay Calculator

  Calculate regular pay, overtime pay and total gross earnings from an hourly wage, split hours and an overtime multiplier.

• Time Card Calculator

  Add up a weekly time card from daily clock-in, clock-out and break times, with weekly overtime and gross pay when you enter a wage.

• Hours to Decimal Calculator

  Convert hours and minutes into decimal hours and total minutes for timesheets, payroll and invoicing.

• VAT Calculator

  Add VAT to a net price or remove it from a tax-inclusive price, using any percentage rate.

• Commission Calculator

  Calculate sales commission at a flat percentage rate and the total earnings once base pay is added.

• Mortgage Calculator

  Estimate the monthly principal-and-interest payment on a mortgage, plus the total repaid and the total interest.

• GPA Calculator

  Calculate a credit-weighted GPA on a 4.0 scale from letter grades, one course per line.

• Date Add or Subtract Calculator

  Add or subtract days, weeks, months or years from any calendar date and see the resulting weekday and date.

• Business Days Calculator

  Count the weekdays between two dates, with the option to include or exclude the final day.

• Day of the Week Calculator

  Find the day of the week for any calendar date, past or future, shown in your language.

• Electricity Cost Calculator

  Estimate how much electricity an appliance uses and what it costs, from its wattage, daily runtime and your price per kWh.

• Paint Calculator

  Estimate how much paint a room needs from its dimensions, the area of doors and windows, the coverage on the tin and the number of coats.

• Concrete Calculator

  Estimate the volume of concrete a slab, path or footing needs, in cubic meters, cubic feet and cubic yards.

• Recipe Scale Calculator

  Scale an ingredient amount from the servings a recipe was written for to the number of servings you actually want.

• Acceleration Converter

  Convert linear acceleration between meters per second squared, feet per second squared and standard gravity.

• Torque Converter

  Convert torque between newton-meters, pound-feet, pound-inches and kilogram-force meters.

• Frequency Converter

  Convert frequency between hertz, kilohertz, megahertz, gigahertz and revolutions per minute.

• Density Converter

  Convert density between kilograms per cubic meter, grams per cubic centimeter and imperial density units.

• Data Transfer Rate Converter

  Convert data rates between bits and bytes per second, from kbps and Mbps to KB/s, MB/s and Gbps.

• Random Yes or No Generator

  Get an unbiased random Yes or No answer, generated in your browser at the press of a button.

• Random Date Generator

  Pick one or more random calendar dates from a range you choose, with both end dates included.

• Random Letter Generator

  Generate random letters in uppercase, lowercase or mixed case, with an option to avoid repeats.

• Word Frequency Counter

  Count how often each word appears in pasted text and rank the results, most frequent first.

• Online Alarm Clock

  Set a browser alarm for a local time of your choice, with an optional label.

• 2FA Code Generator (TOTP)

  Generate time-based authentication codes locally from your own Base32 setup key.

• Scientific Calculator

  Calculate expressions with parentheses, powers, roots, logarithms, and trigonometry in degrees or radians.

• Time Zone Converter & World Clock

  Convert a date and time between world time zones or compare current times with a live world clock.

• Split Bill & Expense Calculator

  Split group expenses equally and calculate who pays whom after accounting for everyone’s contributions.

• Text Diff Checker

  Compare two texts line by line and highlight additions, deletions, and unchanged lines locally in your browser.

• Modulo Calculator

  Find the non-negative remainder and integer quotient when one whole number is divided by another.

• Exponent Calculator

  Raise a finite number to an integer power, including zero and negative exponents.

• Number Base Converter

  Convert whole numbers between binary, octal, decimal, hexadecimal, and any base from 2 to 36.

• Roman Numeral Converter

  Convert whole numbers from 1 to 3,999 to standard Roman numerals and back.