Free Online Tools – Calculators, JSON Formatter, Image Compressor | ToolNest

Calculators

Percentage CalculatorPercent of, ratio and percent change Discount CalculatorSale price, savings and original price Profit Margin CalculatorProfit, margin and markup Average CalculatorMean, median, mode and std dev Percentage Increase / Decrease CalculatorAdd or subtract a percent, % difference Growth Rate CalculatorTotal growth and CAGR Weighted Average CalculatorAverage with weights Ratio CalculatorSolve, simplify and split ratios Decimal CalculatorExact decimal arithmetic

Math

Fraction CalculatorAdd, subtract, simplify, convert Exponent CalculatorSquares, cubes and any power Root CalculatorSquare, cube and nth roots Logarithm Calculatorlog, ln and any base Factorial Calculatorn!, permutations, combinations GCD & LCM CalculatorGreatest common divisor, least common multiple Prime Number CheckerIs it prime? List primes in a range Prime Factorization CalculatorPrime factors and all divisors Binary CalculatorBinary, octal and hex arithmetic Scientific Notation ConverterScientific, E and engineering notation Scientific CalculatorTrig, logs, powers and factorials Standard Deviation CalculatorSample or population SD and variance Quadratic Equation SolverRoots, discriminant and vertex Permutation & Combination CalculatornPr and nCr, exact Rounding CalculatorRound to decimals, sig figs or tens Area CalculatorArea and perimeter of common shapes Volume CalculatorVolume of cubes, cylinders, spheres, cones Fraction, Decimal & Percent ConverterConvert between all three, with steps Function GrapherPlot functions, find zeros and intersections System of Equations SolverExact solutions for linear systems Trigonometry CalculatorExact trig values and the unit circle Matrix CalculatorDeterminant, inverse, multiply, rank

Finance

Mortgage CalculatorMonthly payment and amortization Compound Interest CalculatorGrowth with monthly contributions Simple Interest CalculatorInterest on savings and deposits ROI CalculatorReturn on investment and CAGR Sales Tax / VAT CalculatorAdd or remove tax from a price China Salary After Tax CalculatorTake-home pay after social insurance and IIT China Income Tax CalculatorAnnual IIT, service fees, business income China Annual Bonus Tax CalculatorSeparate vs. combined bonus taxation Loan CalculatorPayment, interest and full schedule Car Loan CalculatorDown payment, monthly payment, total cost Loan Prepayment CalculatorShorter term or lower payment?Inflation CalculatorFuture cost and purchasing power Markup & Pricing CalculatorSet a price from markup or margin Break-Even CalculatorBreak-even units and revenue Savings Goal CalculatorHow much to save, how long it takes Installment APR CalculatorTrue APR of installments and loans

Health

BMI CalculatorBody mass index and healthy range Calorie CalculatorBMR and daily calorie needs Body Fat CalculatorEstimate body fat from measurements Due Date CalculatorEstimate due date from last period Ideal Weight CalculatorHealthy weight range for your height Calorie Deficit CalculatorHow much to eat to lose weight Water Intake CalculatorHow much water to drink a day Sleep CalculatorBest times to sleep and wake Lab Unit ConverterGlucose, cholesterol, creatinine units Height, Weight & Temperature Convertercm↔ft/in, kg↔lb, °C↔°F Heart Rate Zone CalculatorMax heart rate and training zones Waist-to-Hip Ratio CalculatorWHR and waist-to-height ratio Ovulation CalculatorEstimate ovulation and fertile days Period CalculatorPredict your next period Running Pace CalculatorPace, finish time and distance One Rep Max CalculatorEstimate your 1RM and training loads Protein Intake CalculatorHow much protein you need per day Hearing TestHow high can you hear?Macro CalculatorGrams of protein, fat and carbs Child Height PredictorAdult height from parents' heights Blood Type CalculatorChild's blood type from parents

Everyday

Tip CalculatorTip and split per person Split Bill CalculatorWho owes whom, settled Room Area CalculatorFloor area, walls and materials Fuel Cost CalculatorTrip fuel cost and fuel economy Speed, Distance & Time CalculatorSolve any one from the other two Unit Price CalculatorWhich size is the better deal?China Retirement Age CalculatorRetirement date under the new rules Chinese Kinship CalculatorWhat to call relatives in Chinese Chinese ID Number ValidatorCheck digit, birth date and region Typing Speed TestTest your WPM and accuracy Reaction Time TestHow fast are your reflexes?Online MetronomeAdjustable tempo and time signature Tone GeneratorPlay a test tone at any frequency Renovation Material CalculatorTiles, flooring, paint and wallpaper

Sports & Fitness

China University Fitness Test CalculatorScore China's student fitness test China School Fitness Test CalculatorGrades 1–12 fitness test score Race Time PredictorPredict race times from one result VO2 Max CalculatorEstimate VO₂ max from a run or HR Exercise Calorie CalculatorCalories burned by activity Steps to Distance CalculatorConvert steps, km/miles and calories Swim Pace CalculatorPace per 100, SWOLF and CSS Bike Gear Ratio CalculatorGear ratios, cadence and speed HIIT Interval TimerTabata and HIIT workout timer Plank TimerTarget timer plus a 30-day challenge Jump Rope CounterTimed jump rope counting Online ScoreboardScore table tennis, badminton, basketball Tournament Bracket GeneratorRound robin and knockout brackets Random Team GeneratorFair, skill-balanced teams Marathon Split CalculatorGoal time to per-km split times VDOT CalculatorDaniels training paces from a race Track Lap CalculatorLaps and distance on a running track Treadmill Incline CalculatorIncline running to flat-ground pace Running Cadence MetronomeBeat for your target steps per minute Marathon Fueling CalculatorGels, carbs and a race-day schedule CSS Swim CalculatorThreshold pace from a 400/200 test SWOLF & Pool Lap CalculatorSwim efficiency and lengths Watts per Kg CalculatorPower-to-weight and FTP rating FTP Zone CalculatorCoggan power zones and HR zones Bike Tire Pressure CalculatorFront and rear PSI by weight and width Barbell Plate CalculatorWhich plates to load on each side Powerlifting Score CalculatorIPF GL, DOTS and Wilks points RPE CalculatorTraining weight from RPE and reps Training Volume CalculatorSets, reps and volume load FFMI CalculatorFat-free mass index Rep CounterCount reps and time your rest 5/3/1 CalculatorFour-week Wendler program from your 1RM Tennis Scoreboard15/30/40, deuce, tiebreaks Badminton Scoreboard21-point rally scoring with court hints Table Tennis Scoreboard11-point games with serve rotation Volleyball Scoreboard25-point sets, 15-point decider, rotations Basketball Shot ClockGame clock, 24-second clock, fouls Basketball Stats CalculatorTS%, eFG%, efficiency, Game Score League Table GeneratorStandings from match results Bowling Score CalculatorStrikes and spares scored for you Darts 501 ScoreboardCountdown scoring with checkouts Golf Handicap CalculatorWHS Handicap Index and Course Handicap Chess ClockGame clock for chess, Go and xiangqi Elo Rating CalculatorRating change after games Climbing Grade ConverterFrench, YDS, UIAA, V-scale and Font Hiking Time CalculatorTrail time from distance and ascent

Music

Online PianoPlay with your keyboard or touchscreen Guitar Chord FinderGuitar and ukulele chord charts Chord Transposer & Capo CalculatorTranspose a whole chord chart Scale Finder & Circle of FifthsScale notes, chords and key signatures Ear TrainingInterval and chord recognition Numbered Notation ConverterConvert jianpu numbers to note names Note Frequency ChartNote names, Hz and MIDI numbers C0–B8 Tap Tempo BPM CounterTap along to find a song's BPM BPM to ms Delay CalculatorDelay and reverb times from tempo

Science

Sample Size CalculatorHow many responses you need Confidence Interval CalculatorConfidence interval for a mean Percent Error CalculatorMeasured vs. accepted value Significant Figures CalculatorCount and round sig figs Dilution CalculatorSolve C1V1 = C2V2 Periodic TableAll 118 elements with details Molar Mass CalculatorFormula weight and mass percent Chemical Equation BalancerBalance equations, including ionic ones Physics Formula CalculatorSolve school physics formulas

Education

Math Facts Worksheet GeneratorPrintable arithmetic drills by grade Long Arithmetic CalculatorColumn addition to long division, step by step Handwriting Worksheet GeneratorChinese grid sheets and English lines Times TablesMultiplication chart and practice Unit Conversion PracticePrintable metric conversion problems School Age Calculator (China)When a child starts school in China IELTS Score CalculatorBand scores and overall band CET-4/6 Score EstimatorEstimate College English Test scores Exam CountdownDays until your exams Standard Score CalculatorZ-score, T-score and percentile Gaokao Elective Score ConversionChina new gaokao grade conversion Grade StatisticsClass averages, pass rates and rankings Random Name PickerPick students at random, no repeats Class Timetable MakerEdit and print a school timetable Seating Chart GeneratorRandom seating, swaps and printing Spelling Dictation & Word Test MakerRead-aloud dictation and printable tests

Academic

Citation GeneratorAPA, MLA and GB/T 7714 GPA CalculatorWeighted GPA on a 4.0 scale Grade CalculatorWeighted grade and final exam Grade ConverterScore to percent, letter grade, GPA Reading Time CalculatorReading time and reading speed test Study Time PlannerIs there enough time before the exam?Words to Pages CalculatorWord count to page count

Date & Time

Age CalculatorExact age and next birthday Days Between DatesCount days between two dates Date CalculatorAdd or subtract days from a date Business Days CalculatorCount weekdays between dates Unix Timestamp ConverterEpoch time to date and back Birthday CalculatorBirthday countdown, zodiac, birth year from age Countdown CalculatorDays, hours, minutes until a date Time Unit ConverterSeconds, minutes, hours, days Time Difference CalculatorHours between two times, add time Day of the Week CalculatorWhat day of the week is a date?Leap Year CheckerLeap year? Days in year and month Week Number CalculatorWhat week is it? Dates of a week Year ProgressHow much of the year has passed Online ClockCurrent time, digital or analog Online StopwatchStart, stop and record laps Countdown TimerSet a time, get an alarm Pomodoro Timer25 min focus, 5 min break Time Zone ConverterConvert times between cities Date Format ConverterISO 8601, RFC 2822, timestamps 12 / 24 Hour Time ConverterAM/PM to military time and back Chinese Lunar Calendar ConverterConvert between lunar and Gregorian dates Chinese Zodiac CalculatorFind your Chinese zodiac and star sign China Public HolidaysHoliday schedule and make-up workdays

Unit Converters

Length ConverterMeters, feet, inches and more Weight Converterkg, lb, oz, grams and more Temperature ConverterCelsius, Fahrenheit and Kelvin Data Storage ConverterBytes, KB, MB, GB and TB Area ConverterSquare meters, feet, acres, hectares Volume ConverterLiters, gallons, cups, tablespoons Speed Converterkm/h, mph, m/s and knots Number Base ConverterBinary, octal, decimal, hex Roman Numeral ConverterNumbers to Roman numerals and back Chinese Number ConverterNumbers to Chinese numerals and back Number FormatterThousands separators, percents, K/M/B Pressure Converterpsi, bar, kPa, atm and mmHg Energy ConverterCalories, kJ, kWh and BTU Power ConverterWatts, kW, horsepower, BTU/h Angle ConverterDegrees, radians, arcminutes Fuel Economy Convertermpg, L/100km and km/L Shoe & Clothing Size ConverterShoe, top and waist size charts

Text Tools

Word CounterWords, characters, reading time Case ConverterUPPER, lower, camelCase, snake_case Remove Duplicate LinesRemove duplicate and empty lines Sort LinesSort, reverse or shuffle lines Find and ReplaceBulk replace with regex support Text DiffHighlight differences between texts Whitespace RemoverRemove empty lines, extra spaces, line breaks Reverse TextBackwards text, lines or words Text RepeaterRepeat text N times Text Splitter & JoinerSplit by delimiter, join lines Text TruncatorCut text to N characters or bytes Add Prefix / Suffix & Line NumbersPrefix, suffix, number lines Simplified ⇄ Traditional ChineseConvert Simplified and Traditional Chinese Chinese to Pinyin ConverterPinyin with tone marks or numbers

Developer Tools

JSON FormatterValidate, beautify, minify JSON JSON to CSV ConverterConvert JSON and CSV both ways Base64 Encode / DecodeEncode and decode Base64 URL Encode / DecodePercent-encode and decode URLs UUID GeneratorBulk random UUID v4 JWT DecoderDecode JWT header and payload Regex TesterLive regex matching and groups XML FormatterBeautify, minify and validate XML HTML FormatterBeautify, minify, check tags CSS FormatterBeautify and minify CSS JavaScript FormatterBeautify and minify JS SQL FormatterBeautify and minify SQL Markdown Preview & to HTMLLive Markdown preview, export HTML HTML to MarkdownConvert HTML into Markdown HTML Entity Encoder / DecoderEscape and unescape HTML Unicode ConverterText ↔ \uXXXX escapes Text to Binary / Hex / ASCIIText to binary, hex, ASCII and back String Escape / UnescapeJSON, JS, regex, SQL, CSV escaping Hash Generator (MD5 / SHA)MD5, SHA-1, SHA-256, SHA-512, HMAC HTTP Status CodesWhat 200, 301, 404, 500 mean MIME Types LookupFile extensions to Content-Type User-Agent ParserDetect browser, OS and device URL Parser & BuilderSplit URLs, parse and build query strings Format ValidatorValidate emails, IPs, URLs and more JSON Diff & MergeCompare two JSON files and merge them Cron Expression GeneratorExplain cron and preview run times YAML ⇄ JSON ConverterConvert YAML to JSON and back JSON to CodeJSON to TypeScript, Go, Java types IP Subnet CalculatorCIDR, netmask and host range Chmod CalculatorLinux permissions: octal ⇄ symbolic AES Encrypt & DecryptAES-GCM, CBC, CTR and ECB online

AI Tools

Prompt GeneratorBuild structured AI prompts Prompt Template EditorFill variables, save and share prompts Token CounterEstimate tokens and context usage

Color Tools

Color ConverterHEX, RGB, HSL and CMYK Random Color GeneratorRandom HEX, RGB and HSL colors CSS Gradient GeneratorLinear, radial, conic and random Color Palette GeneratorComplementary, analogous, 50–950 shades Color Contrast CheckerWCAG AA / AAA contrast Color Opacity CalculatorRGBA, 8-digit HEX, blended color

Image Tools

Image CompressorShrink image file size in bulk Image ConverterConvert JPG, PNG and WebP Image ResizerResize by pixels or percent Passport Photo MakerChange background, crop to size, print sheet Crop ImageCrop to a ratio or exact pixels Rotate & Flip ImageRotate any angle or mirror Watermark ImageAdd a text watermark, tiled or in a corner Image Grid SplitterSplit a photo into a 3×3 grid Image StitcherCombine images into one long image HEIC to JPGConvert iPhone photos to JPG Image to Base64Convert images to Base64 and back Favicon GeneratorCreate favicon.ico and app icons SVG to PNGConvert SVG to high-res PNG or JPG Image Color PickerPick colors and palette from an image

PDF Tools

Merge PDFCombine multiple PDFs into one Split PDFSplit by page ranges or extract pages JPG to PDFCombine images into one PDF PDF to JPGExport PDF pages as JPG or PNG Rotate PDFRotate all or individual pages Delete PDF PagesRemove pages you don't need Add Page Numbers to PDFNumber the pages of a PDF Watermark PDFAdd a text watermark, tiled or centered Compress PDFShrink scanned and image-heavy PDFs

Generators

Password GeneratorStrong random passwords QR Code GeneratorQR codes for text, Wi-Fi, email Random Number GeneratorRandom numbers in any range Lorem Ipsum GeneratorPlaceholder text for mockups Password Strength CheckerHow strong is your password?Random String GeneratorRandom letters, digits, PINs, codes Random Name PickerPick winners, shuffle, make groups Random Date GeneratorRandom dates and times in a range Random IP & MAC GeneratorRandom IPv4, IPv6 and MAC addresses Random Username & Title GeneratorUsernames, file names, titles, sentences Table GeneratorSpreadsheet data to Markdown / HTML List GeneratorText to HTML or Markdown lists Mock Data GeneratorFake JSON, CSV, XML, SQL data SQL Create Table GeneratorBuild CREATE TABLE visually CSS Box Shadow GeneratorDesign box-shadow visually CSS Border Radius GeneratorDesign border-radius visually CSS Button GeneratorDesign button styles visually Barcode GeneratorCode 128, EAN-13, UPC and more

SEO Tools

SERP PreviewPreview Google search snippets Slug GeneratorTurn titles into URL slugs Meta Tag GeneratorSEO and Open Graph tags Keyword Density CheckerKeyword frequency and density Heading Structure CheckerCheck H1 and heading hierarchy Robots.txt GeneratorCreate crawler rules XML Sitemap GeneratorURL list to sitemap.xml Schema Markup GeneratorJSON-LD for FAQ, breadcrumbs, articles