Free online calculators
Health, finance, dates, units and developer tools. Everything runs in your browser — no sign-up, no limits.
Money and loans
Discount calculatorSale price, percentage off and reverse priceTip calculatorTip and per-person splitBill split calculatorEven split · per-item extrasLoan repayment calculatorAmount · rate · term → monthly paymentLoan repayment methods comparedThree repayment methods, one loanRefinance break-even calculatorIs refinancing worth it?Loan-to-value (LTV) calculatorLTV, equity and headroomDeposit interest calculatorLump sum · simple or compoundRecurring deposit calculatorSame amount every monthSavings goal calculatorWork backwards from the targetDividend calculatorDividend income · capital requiredInflation calculatorFuture cost · today’s valueRetirement savings calculatorBuild-up and draw-downBreak-even calculatorBreak-even price · break-even volumeAverage cost calculatorWeighted average of your buysCurrency converterLive reference ratesRental yield calculatorGross yield · yield on cash investedSimple interest calculatorInterest on principal onlyROI calculatorROI · CAGRCompound interest calculatorYear-by-year compound growthCurrency exchange fee calculatorSpread, preferential rate, and the fee hiding in bothSalary to hourly wage calculatorMonthly/annual salary → hourly and daily wageMonthly to annual salary calculatorMonthly pay → annual salaryOverdraft interest calculatorAverage balance drawn × rate × daysRevolving credit interest calculatorBalance and payment → payoff time and total interest
Home and car
Appliance electricity cost calculatorRunning cost of one applianceCar finance calculatorMonthly payment · total interestCar running cost calculatorYearly cost of keeping a carFuel economy calculatorkm/L · L/100 km · mpgFuel cost calculatorFuel cost for a tripEV charging cost calculatorCharging cost · range addedVolumetric weight calculatorDimensional weight of a parcelShoe size converterFoot length to US · UK · EU sizesPet age calculatorDog and cat age in human yearsCoffee Ratio CalculatorCoffee-to-water ratio for any brew methodRice-to-Water Ratio CalculatorRice-to-water ratio for any measuring cupTV Size CalculatorTV size from viewing distanceMonitor Size CalculatorMonitor size and pixel density for your deskDesk Height CalculatorDesk and chair height from your heightFeels-like temperature calculatorHeat index and wind chillMobile data usage calculatorGB per hour by activity typeCharging time calculatormAh/Wh + charger watts → charge time
Body and health
Daily calorie calculatorTDEE by activity levelProtein intake calculatorDaily protein by goalBody fat percentage calculatorTape method · BMI estimateExercise calorie calculatorCalories burned by activityCaffeine half-life calculatorCaffeine left at bedtimeBlood pressure category checkerRead your numbersBMI calculatorBMI with healthy weight rangeChild height predictorMid-parental height with real rangesIdeal body weight calculatorIdeal weight and healthy BMI rangeOne-rep max calculator1RM and training percentagesRunning pace calculatorPace and splits from a target timeSleep cycle calculatorBedtime and wake time by sleep cycleAlcohol calorie calculatorDrinks and glasses in, calories outBMR calculatorHarris-Benedict vs Mifflin-St JeorQuit-smoking savings calculatorCigarettes/day and pack price → money savedRace time predictorOne race time in, four predictions outBaby formula amount calculatorWeight-based feeding guidelinePet food amount calculatorWeight and life-stage based feeding guidelineWater intake calculatorBody weight · activity · climateBlood type inheritance calculatorABO · Rh · genotype oddsMacro calculatorBMR · TDEE · protein / carbs / fat gramsTarget heart rate calculatorMax HR · Karvonen method · 5 training zonesWaist-to-hip ratio calculatorWaist ÷ hip · WHO risk thresholds
Dates and hours
Age calculatorExact age between two datesDay counterCountdown and days betweenTime difference calculatorDifference · add · subtractBirthday calculatorDays lived · next birthdayOvulation calculatorFertile window · next periodDue date calculatorDue date · weeks alongFertility probability calculatorMonthly and yearly odds by ageImplantation calculatorImplantation window · test dateSafe period calculator (Standard Days Method)Fertile window · Standard Days MethodChinese gender predictorTraditional gender guess · just for funWork hours calculatorClock-in to clock-out, minus breaksOvertime pay calculatorWage × hours × multiplier
Numbers and units
Length convertermm · cm · m · km · in · ft · yd · mi · NMWeight convertermg · g · kg · t · oz · lb · stoneTemperature converter°C · °F · K · °RNumber base converterBinary · octal · decimal · hexPercentage calculatorRatio · part · increase and decreaseMean, median and standard deviation calculatorMean · median · standard deviationGPA calculatorCredit-weighted GPAFinal grade calculatorCurrent grade · exam weight · targetSpeed, distance & time calculatorSolve for distance, speed, or timeVolume convertermL · L · m³ · tsp · tbsp · cup · fl oz · gal · pt
Developer tools
JSON formatterFormat · validate · minifyBase64 encoder and decoderEncode · decodeURL encoder and decoderPercent-encode · decodeUnix timestamp converterTimestamp ↔ dateJWT decoderDecode header and payloadSHA-256 and SHA-512 generatorSHA-256 · SHA-512Regex testerPattern · flags · matchesUUID generatorRandom v4 UUIDsColour converterHEX ↔ RGB ↔ HSLCron expression helperExplain · presets · field referenceSQL formatterFormat · indent · keyword caseWord and character counterCharacters · words · sentences · bytesText diffLine-by-line comparisonAI token cost calculatorToken estimate · model pricing · per-request cost
Also in other sections
Discount CalculatorFind the final price and how much you save from a list price and a percentage off.Tip CalculatorAdd a tip to the bill and split it across the table.Split the BillDivide a total across people and round up to a convenient amount.ROI CalculatorGet return on investment and profit from what you put in and got back.Simple InterestFind the final amount when interest is paid on the principal only.Compound InterestFind the final amount when interest earns interest.BMI CalculatorGet your body mass index and ideal weight from height and weight.BMR CalculatorFind the minimum calories your body burns doing nothing at all.Sleep Cycle CalculatorPlan sleep in 90-minute cycles so you wake between them.Daily Water IntakeEstimate how much water to drink from body weight and exercise time.Resale Value DepreciationWhat something is worth after losing a fixed share of its value each year.Hourly Pay to MonthlySee monthly and yearly income from an hourly rate and the hours you work in a month.