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Every Kwikfig tool, in one directory. Search, or browse by category — each one is free and runs entirely in your browser.

Student & Grade Calculators (13)

Math Calculators (17)

Percentage Calculator∑Work out percentages three ways — find the part, find the percent, or measure the change between two values — with full working shown for every answer.Open tool →Fraction Calculator∑Add, subtract, multiply and divide fractions, then simplify the result to lowest terms and a mixed number, with every common-denominator step shown.Open tool →Average Calculator∑Find the mean, median, mode and range of any list of numbers in one pass, with the sorted order and sum shown so you can check the result yourself.Open tool →Standard Deviation Calculator∑Calculate population and sample standard deviation side by side, with the mean, squared deviations and variance shown step by step for your data set.Open tool →Scientific Calculator∑A full scientific calculator with trig, logarithms, powers, roots and constants — in degrees or radians — with a clear history of what you entered.Open tool →Ratio Calculator∑Simplify ratios to lowest terms, scale them up or down, and solve for a missing value in a proportion, with the common factor and working shown.Open tool →Logarithm Calculator∑Find logarithms in any base — common log, natural log, or your own — using the change-of-base rule, with the power check shown beside every answer.Open tool →Exponent Calculator∑Raise any base to any power, including negative and fractional exponents, and see the repeated multiplication or root step that produces the answer.Open tool →Square Root Calculator∑Find exact and decimal square roots, simplify surds like √72 into 6√2, and check the result by squaring it back, all with the working shown.Open tool →LCM Calculator∑Find the least common multiple of two or more numbers using prime factors or listing multiples, with the shared multiples highlighted in the working.Open tool →GCF Calculator∑Find the greatest common factor of two or more numbers by prime factorisation or Euclid's method, with every division step shown in the working.Open tool →Factorial Calculator∑Compute exact factorials up to 1000! as full big numbers, see the digit count, and compare Stirling's approximation beside the exact value.Open tool →Rounding Calculator∑Round any number to decimal places, to the nearest ten, hundred or thousand, or to significant figures, using the half-up rule with the working shown.Open tool →Probability Calculator∑Work out the probability of a single event or two events together — both, at least one, or neither — as a fraction, a decimal and a percentage.Open tool →Permutation & Combination Calculator∑Calculate permutations and combinations from n and r with the factorial substitution shown step by step, plus a plain test for which one your problem needs.Open tool →Quadratic Equation Solver∑Solve any quadratic equation with the formula, see the discriminant verdict, the factorisation where it exists, and the vertex of the parabola.Open tool →Pythagorean Theorem Calculator∑Find any side of a right-angled triangle from the other two — hypotenuse or leg — with the squaring and root steps shown and classic triples recognised.Open tool →

Finance Calculators (19)

Loan / EMI Calculator$Work out the monthly payment, total interest and full amortisation schedule for any loan from its amount, rate and term — with the first payments broken down.Open tool →Mortgage Calculator$Calculate the monthly mortgage payment on the amount you actually borrow after your down payment, with optional tax and insurance added on top, line by line.Open tool →Auto Loan Calculator$Find the real monthly cost of a car loan: price minus down payment and trade-in gives the amount financed, then compare terms to see the total cost of borrowing.Open tool →Amortization Calculator$See the full amortisation schedule for a loan and what extra monthly payments really do: move the payoff date forward and cut the total interest, in hard numbers.Open tool →Compound Interest Calculator$Project how money grows with compound interest across compounding frequencies, with or without regular contributions, and see the balance for every single year.Open tool →Simple Interest Calculator$Calculate simple interest with I = PRT, see the balance year by year, and compare it honestly against compound interest on the same money over the same period.Open tool →Future Value Calculator$Project the future value of a lump sum, a stream of regular contributions, or both together — with deposits and growth reported as separate, checkable numbers.Open tool →Savings Goal Calculator$Work backwards from a savings target: enter the amount you need, the date you need it by and the rate you expect, and get the exact monthly deposit that gets you there.Open tool →Credit Card Payoff Calculator$See how long a credit card balance really takes to clear at a fixed payment versus the minimum payment — and exactly how much interest each path costs you in total.Open tool →Debt Payoff Calculator$Compare the avalanche and snowball debt payoff methods side by side on your own balances: total interest, payoff time and the order each method clears your debts.Open tool →Retirement Savings Calculator$Project a retirement savings balance to a target age from your current savings, monthly contributions and an assumed growth rate — year-by-year arithmetic, nothing more.Open tool →Inflation Calculator$Translate money across time at an inflation rate you choose: what a future sum will cost, and what today's money will actually buy after years of rising prices.Open tool →APY Calculator$Convert a stated APR into the true annual percentage yield for any compounding frequency — monthly, daily or continuous — so savings offers can be compared fairly.Open tool →ROI Calculator$Calculate return on investment as a total percentage and as an annualised rate, so a gain over six months and a gain over six years can be compared honestly.Open tool →Break-Even Calculator$Find the break-even point in units and in revenue from your fixed costs, variable cost per unit and selling price — with contribution margin explained in plain terms.Open tool →Profit Margin Calculator$Calculate profit margin and markup together from cost and price, and finally separate the two numbers that business conversations constantly confuse with each other.Open tool →Discount Calculator$Work out the price after a discount — including stacked discounts calculated correctly, where 20% off followed by 10% off is 28% off in total, never the 30% it looks like.Open tool →Sales Tax / VAT Calculator$Add sales tax or VAT to a price, or strip it back out of a tax-inclusive price to find the net amount — you enter the rate, because no built-in table can know yours.Open tool →Salary to Hourly Converter$Convert an annual salary to its hourly, daily, weekly, biweekly and monthly equivalents — or run it backwards from an hourly rate — using your actual working hours.Open tool →

Unit Converters (13)

Popular Conversions (18)

Date & Time Tools (12)

Age Calculator◷Find your exact age in years, months and days from any date of birth, plus total days lived, the weekday you were born and your next birthday countdown.Open tool →Days Between Dates Calculator◷Count the calendar days and business days between two dates, with the end-date convention stated openly and a weeks-and-days breakdown alongside.Open tool →Date Calculator◷Add or subtract days, weeks, months or years from any date — in calendar days or business days — and see the resulting date, its weekday and the true span crossed.Open tool →Day of Week Calculator◷Find the day of the week for any date — past or future — with its day of the year, ISO week number, leap-year status and days left in the year.Open tool →Days Until Calculator◷Count the days until any date — a birthday, deadline, holiday or launch — in days, weeks, hours and minutes, with past dates shown honestly as days since.Open tool →Time Duration Calculator◷Work out the time between two clock times — shifts, flights, study sessions — with overnight spans handled, in hours and minutes, decimal hours and total minutes.Open tool →Time Card Calculator◷Total a week of clock-in and clock-out times with unpaid breaks deducted per day, and split the week into regular hours and overtime past 40.Open tool →Week Number Calculator◷Convert any date to its ISO week number and ISO year — and convert an ISO week back into its Monday-to-Sunday dates — using the full ISO-8601 rules.Open tool →Time Zone Converter◷Convert a date and time between time zones with real daylight-saving rules — see the same moment in UTC, London, New York, Karachi, Tokyo, Sydney and more, with day shifts marked.Open tool →Hours Calculator◷Add up a list of hours and durations — timesheet entries, study sessions, project time — in mixed formats, with a running total and decimal hours for payroll.Open tool →Leap Year Calculator◷Check whether any year is a leap year, see the divisible-by-4, 100 and 400 rule applied step by step, and find the leap years around it and February's length.Open tool →Stopwatch & Timer◷A free online stopwatch with laps and a countdown timer on one page — no app, no sign-up — timed from your device clock to a tenth of a second.Open tool →

Text Tools (15)

Word Counter¶Count words, characters, sentences and paragraphs as you type, with reading time at 200 words per minute and speaking time alongside — all in your browser.Open tool →Case Converter¶Convert any text between UPPERCASE, lowercase, Title Case, Sentence case, camelCase, PascalCase, snake_case and more — every style shown at once, instantly.Open tool →Remove Duplicate Lines¶Remove duplicate lines from any list while keeping first occurrences in order, with optional sorting, trimming and case-insensitive matching built in.Open tool →Lorem Ipsum Generator¶Generate classic filler text by paragraphs, sentences or words, with an optional classic opening, a choice of length and one-click copying for layouts.Open tool →Text Diff Checker¶Compare two versions of any text side by side and see exactly which words were added, removed or left unchanged, with counts for each kind of change.Open tool →Find and Replace¶Find and replace words or patterns across a whole document at once, with match counts, whole-word and case options, plus a full regular-expression mode.Open tool →Word Frequency Counter¶Count how often every word appears in your text, ranked in a frequency table with an optional stop-word filter and a downloadable CSV of the results.Open tool →Reverse Text¶Reverse text by characters, by words or by lines — three separate modes for flipping a string, a sentence or a whole list in the opposite order.Open tool →Slug Generator¶Turn any title or heading into a clean URL slug: accents are transliterated, punctuation is removed and words are joined exactly how web addresses need.Open tool →Remove Line Breaks¶Remove unwanted line breaks from copied text and rejoin it with spaces, keep paragraph gaps, or strip breaks entirely — the PDF copy-paste cleanup tool.Open tool →Number to Words Converter¶Convert numbers into English words for cheques, contracts and forms — cardinal and ordinal forms, decimals and negatives, up to just below a quadrillion.Open tool →Morse Code Translator¶Translate text to Morse code and Morse code back to text, with the full A–Z and 0–9 code table on the page and both directions handled in your browser.Open tool →Text Sorter¶Sort a list of lines alphabetically, numerically or by length, ascending or descending, with an optional duplicate-removal pass in the same operation.Open tool →Add Line Numbers¶Add line numbers to any block of text with your choice of starting number, step, zero-padding and separator — ready to paste into documents and code.Open tool →Strip HTML Tags¶Strip HTML tags, scripts and styles from pasted markup and return clean plain text, with an option to keep paragraph and line breaks where they belong.Open tool →

Developer Tools (18)

JSON Formatter & Validator{ }Format and validate JSON in your browser — pretty-print or minify with your choice of indent, and see the exact line and column when the syntax breaks.Open tool →Base64 Encoder / Decoder{ }Encode text to Base64 or decode it back — UTF-8 safe, with a URL-safe variant — using the full 64-character alphabet and padding rules printed on the page.Open tool →URL Encoder / Decoder{ }Encode a whole URL or a single query value with the right mode — component or full — and decode percent-escapes back to the text they came from, in your browser.Open tool →UUID Generator{ }Generate bulk version-4 UUIDs — one or a hundred at a time — built directly from cryptographically secure random bytes with the RFC 4122 bits set for you.Open tool →Hash Generator (SHA){ }Compute SHA-1, SHA-256, SHA-384 and SHA-512 hashes of text or a file, entirely on your device with the Web Crypto API — nothing is uploaded or stored.Open tool →Unix Timestamp Converter{ }Convert Unix timestamps to human dates and back — epoch seconds or milliseconds, UTC and your local time side by side, with a live ticking current time.Open tool →JWT Decoder{ }Decode a JSON Web Token's header and payload in your browser — claims in a table, exp and iat as real dates, expiry judged against now. Decoding only, never verification.Open tool →Regex Tester{ }Test regular expressions live — matches highlighted in your text, capture and named groups listed, flags as toggles, and a syntax cheat-sheet on the page.Open tool →Color Converter{ }Convert colours between hex, RGB, HSL and HSV with a picker and numeric fields — plus complementary, analogous, triadic and split-complementary harmonies.Open tool →Contrast Checker{ }Check text and background colour pairs against WCAG contrast rules — the exact ratio plus pass or fail for AA and AAA, normal and large text, live as you pick.Open tool →CSV to JSON Converter{ }Convert CSV to a JSON array of objects — delimiter detected automatically, quoted fields handled properly — and convert JSON back to CSV in the same tool.Open tool →HTML Entity Encoder / Decoder{ }Encode special characters as named or numeric HTML entities and decode entities back to text, with a reference table of the entities you will actually meet.Open tool →XML Formatter{ }Pretty-print XML with consistent indentation or minify it back down, with mismatched and unclosed tags reported by name instead of a silent failure.Open tool →SQL Formatter{ }Reformat tangled SQL into readable, clause-per-line queries — keywords upper or lower case, string literals left untouched — entirely in your browser.Open tool →Markdown to HTML Converter{ }Convert Markdown to clean HTML as you type, with a live preview beside the source — headings, lists, links and code rendered by GitHub-flavoured rules.Open tool →Cron Expression Generator{ }Build cron expressions by pointing and clicking, or paste one in — with a plain-words summary and the next five run times computed against your local clock.Open tool →IP Subnet Calculator{ }Work out any IPv4 subnet from an address and a prefix or netmask — network, broadcast, wildcard, usable host range and counts, with the /31 and /32 rules handled.Open tool →Number Base Converter{ }Convert integers between any bases from 2 to 36 — binary, octal, decimal, hex and beyond — with arbitrary precision, digit validation and all four common bases at once.Open tool →

Everyday Tools & Generators (9)

QR Code Generator✦Build a QR code from a link, text, Wi-Fi login, email, phone or SMS payload and download it as PNG or SVG — no expiry, no tracking redirect, no watermark.Open tool →Password Generator✦Generate strong passwords at your choice of length and character sets — drawn from the browser's cryptographic random source, with the entropy shown in bits.Open tool →Password Strength Checker✦Check a password's entropy, character pool and crack time at four stated guessing rates — and see whether it appears on a list of common passwords.Open tool →Tip & Bill Split Calculator✦Work out the tip, the total and exactly what each person owes when the bill is split — with preset tip rates, custom percentages and cent-exact rounding.Open tool →Random Number Generator✦Generate random integers in any range, with a unique-numbers mode for draws and lotteries — sampled without bias from the browser's cryptographic source.Open tool →Dice Roller✦Roll dice of any size — d4 to d100 — with an optional modifier, session statistics, and the exact probability distribution for your dice combination.Open tool →Random Name Picker✦Pick a random name — or several — from your own list: classroom draws, raffle winners and team picks, with a remove-the-winner flow built in.Open tool →Typing Speed Test✦Measure your typing speed in words per minute with live gross and net WPM, position-by-position accuracy, and your choice of a 60-second or free-run mode.Open tool →Unit Price Calculator✦Compare products by their true unit price — per 100 g, per kilogram, per litre or per item — with mixed metric and imperial pack sizes normalised for you.Open tool →

Sports & Fitness Calculators (6)

Running Pace Calculator⚑Work out running pace, finish time or distance from any two of the three — with an even split table per kilometre or mile for your race distance.Open tool →Race Time Predictor⚑Predict your finish time at 5K, 10K, half marathon, marathon and more from one recent race result, using Pete Riegel's classic endurance formula.Open tool →Race Split Calculator⚑Build a per-kilometre or per-mile split table for your goal time — even, negative or positive splits that add up to the finish time exactly.Open tool →One-Rep Max Calculator⚑Estimate your one-rep max from any set with the Epley and Brzycki formulas, then read training weights from 100% down to 50% of that max.Open tool →VO2 Max Calculator⚑Estimate your VO2 max from the Rockport one-mile walk test or the Cooper 12-minute run, and see your fitness category for your age and sex.Open tool →Golf Handicap Calculator⚑Calculate a World Handicap System score differential from a round, or turn your handicap index into course and playing handicaps for any tee.Open tool →

Health & Body Calculators (12)

BMI Calculator♥Calculate body mass index from weight and height using the WHO formula, in metric or imperial, and locate the result in the published WHO bands.Open tool →BMR & Calorie Calculator (TDEE)♥Estimate basal metabolic rate with the Mifflin-St Jeor equation and scale it to total daily energy expenditure with the standard activity factors.Open tool →Ideal Weight Calculator♥Compare the four published ideal-weight formulas — Devine, Hamwi, Robinson and Miller — side by side at any height, with the BMI 18.5–24.9 range alongside.Open tool →Body Fat Calculator♥Estimate body fat percentage from tape measurements with the US Navy circumference method, and split body weight into fat mass and lean mass.Open tool →Pregnancy Due-Date Calculator♥Calculate an estimated due date from last period, conception date or an ultrasound scan using Naegele's rule, with trimester milestone dates listed.Open tool →Macro Calculator♥Split a calorie total into protein, carbohydrate and fat grams for five named presets, using the standard 4, 4 and 9 kcal per gram conversion.Open tool →Calories Burned Calculator♥Estimate energy expenditure for common activities from body weight and duration, using MET values from the published Compendium of Physical Activities.Open tool →Water Intake Calculator♥Work out a daily water figure from the 35 ml per kilogram rule of thumb, with an exercise addition and conversions to litres, cups and fluid ounces.Open tool →Lean Body Mass Calculator♥Calculate lean body mass with three published formulas — Boer, James and Hume — shown together so the spread between methods stays visible.Open tool →Body Surface Area Calculator♥Calculate body surface area in square metres with the Mosteller and Du Bois formulas — the two standard published equations, shown side by side.Open tool →Heart Rate Zone Calculator♥Calculate five heart-rate training zones with the Karvonen formula, using either the Fox or Tanaka estimate of maximum heart rate.Open tool →Sleep Calculator♥Work out bedtimes and wake times in complete 90-minute sleep cycles, with an adjustable allowance for the time taken to fall asleep.Open tool →

Home & DIY Calculators (12)

Square Footage Calculator⌂Calculate the area of rectangles, circles and triangles and add them into one total — the starting figure for paint, tile, flooring and garden materials.Open tool →Paint Calculator⌂Estimate paint for a room from its dimensions — wall area minus standard doors and windows, multiplied by coats and divided by the coverage rate.Open tool →Concrete Calculator⌂Calculate concrete volume for slabs, footings and round columns in cubic yards and feet, and convert the volume into pre-mix bags by their stated yields.Open tool →Tile Calculator⌂Count tiles for a floor or wall from the area and tile size — including the grout gap in each tile's effective area, a layout waste factor and boxes.Open tool →Flooring Calculator⌂Work out how many boxes of laminate, vinyl or engineered flooring a room needs — area plus the waste factor for the laying pattern, divided by box coverage.Open tool →Mulch Calculator⌂Calculate mulch volume from bed area and depth in cubic yards, cubic feet and standard bags — with a depth-to-coverage table for one cubic yard.Open tool →Gravel Calculator⌂Calculate gravel volume and weight for paths, drives and drainage — volume from area and depth, weight from the stated density of the material chosen.Open tool →Fence Materials Calculator⌂Count fence sections, posts, panels and rails for a run of any length — sections from the panel width, posts at sections plus one, gates deducted from panels.Open tool →BTU Calculator⌂Estimate the BTU size for heating or cooling a room from floor area with published rule-of-thumb adjustments for ceiling height, insulation, sun and occupants.Open tool →Roof Pitch Calculator⌂Convert between roof pitch, angle and rafter length — pitch as rise over 12, the angle in degrees and the multiplier that turns a horizontal run into a rafter.Open tool →Board Foot Calculator⌂Calculate board feet from thickness, width and length, total a cut list, and price it — with a table of board feet for common nominal sizes at 8 ft.Open tool →Stair Calculator⌂Design a straight staircase from its total rise — riser count and height, tread depth by Blondel's rule, total run, stringer length and stair angle.Open tool →