Tool category
Calculators
Fast, accurate calculators for everyday numbers. Choose from 204 complete, ready-to-use tools.
All calculators
204 free tools available now.
Calculator
Calculate sums, percentages, decimals, and everyday totals.
Open toolPercentage Calculator
Calculate percentages, ratios, and percentage change.
Open toolAge Calculator
Find an exact age in years, months, and days.
Open toolTip & Bill Split Calculator
Calculate a tip and split the total between people.
Open toolDiscount Calculator
Find a sale price and see exactly how much you save.
Open toolAverage Calculator
Calculate average, median, sum, minimum, and maximum.
Open toolTime Duration Calculator
Find elapsed hours and minutes between two times.
Open toolMortgage Calculator
Estimate a fixed-rate US mortgage payment including optional property tax, insurance, and HOA costs.
Open toolLoan Calculator
Calculate monthly payment and total interest for a fixed-rate loan.
Open toolAuto Loan Calculator
Estimate a US auto-loan payment using price, trade-in, down payment, tax, fees, rate, and term.
Open toolPayment Calculator
Calculate the periodic payment for a fixed-rate loan using a term in months.
Open toolAmortization Calculator
Calculate a fixed-rate payment, total interest, and the first payment's principal and interest split.
Open toolInvestment Calculator
Estimate how an initial investment and monthly contributions may grow over time.
Open toolCompound Interest Calculator
Estimate compound growth with an initial balance, monthly contributions, time, rate, and compounding frequency.
Open toolSalary Calculator
Convert between hourly pay and annual gross salary using your weekly hours and working weeks.
Open toolSales Tax Calculator
Add a US sales-tax rate to a pre-tax purchase amount.
Open toolSavings Calculator
Estimate a future savings balance from an initial deposit and monthly contributions.
Open toolSimple Interest Calculator
Calculate simple interest and ending balance from principal, annual rate, and time.
Open toolVAT Calculator
Add VAT to a net amount or extract VAT from a VAT-inclusive amount.
Open toolDepreciation Calculator
Estimate straight-line depreciation, accumulated depreciation, and book value.
Open toolAverage Return Calculator
Calculate arithmetic average return and compounded average growth from a list of period returns.
Open toolMargin Calculator
Calculate gross profit, profit margin, and markup from cost and selling price.
Open toolDebt-to-Income Ratio Calculator
Calculate monthly debt payments as a percentage of gross monthly income.
Open toolPersonal Loan Calculator
Estimate monthly payment and total interest for a fixed-rate personal loan.
Open toolBusiness Loan Calculator
Estimate payments and interest for a fixed-rate business loan.
Open toolBoat Loan Calculator
Estimate payments and interest for a fixed-rate boat loan.
Open toolROI Calculator
Calculate investment gain or loss and return on investment percentage.
Open toolPayback Period Calculator
Estimate how long a constant annual cash flow takes to recover an initial investment.
Open toolPresent Value Calculator
Calculate the present value of a lump sum using a stated rate, time, and compounding frequency.
Open toolFuture Value Calculator
Calculate the future value of a lump sum using a stated rate, time, and compounding frequency.
Open toolCommission Calculator
Calculate sales commission and total gross pay including an optional base amount.
Open toolDown Payment Calculator
Calculate a down payment amount and remaining loan from a purchase price and percentage.
Open toolInterest Rate Calculator
Estimate the annual fixed interest rate implied by a loan amount, monthly payment, and term.
Open toolFraction Calculator
Add, subtract, multiply, or divide two fractions and simplify the result.
Open toolStandard Deviation Calculator
Calculate mean, variance, and population or sample standard deviation.
Open toolPercent Error Calculator
Calculate absolute error and percent error between observed and accepted values.
Open toolExponent Calculator
Raise any real base to a real exponent.
Open toolHalf-Life Calculator
Calculate the remaining amount after a given number of half-lives.
Open toolQuadratic Formula Calculator
Solve ax² + bx + c = 0 and show real or complex roots.
Open toolSlope Calculator
Calculate slope, rise, run, and line equation from two points.
Open toolLog Calculator
Calculate a logarithm using any positive base other than one.
Open toolPermutation and Combination Calculator
Calculate nPr permutations or nCr combinations exactly using whole numbers.
Open toolDistance Calculator
Calculate straight-line distance and midpoint between two 2D coordinates.
Open toolCircle Calculator
Calculate diameter, circumference, and area from a circle's radius.
Open toolPythagorean Theorem Calculator
Calculate the hypotenuse of a right triangle from its two legs.
Open toolRoot Calculator
Calculate square roots or any real nth root.
Open toolLeast Common Multiple Calculator
Find the least common multiple of two whole numbers.
Open toolGreatest Common Factor Calculator
Find the greatest common factor of two whole numbers.
Open toolFactor Calculator
List every positive factor of a whole number.
Open toolRounding Calculator
Round a number to a chosen number of decimal places.
Open toolPrime Factorization Calculator
Break a positive whole number into its prime factors.
Open toolDate Calculator
Find the exact number of days, weeks, and calendar direction between two dates.
Open toolDay Counter
Count elapsed or inclusive calendar days between two dates.
Open toolDay of the Week Calculator
Find the weekday and day of year for any valid Gregorian calendar date.
Open toolTime Calculator
Add or subtract hours and minutes from a clock time.
Open toolHours Calculator
Add a list of decimal-hour entries and convert the total to hours and minutes.
Open toolGPA Calculator
Calculate a credit-weighted GPA from grade points and course credits.
Open toolGrade Calculator
Calculate a percentage grade from points earned and points possible.
Open toolHeight Calculator
Convert a height in feet and inches to inches, centimeters, and meters.
Open toolSquare Footage Calculator
Calculate rectangular floor or wall area in square feet and square meters.
Open toolConcrete Calculator
Estimate concrete volume for a rectangular slab and common 80 lb bag quantity.
Open toolFuel Cost Calculator
Estimate US trip fuel use and cost from miles, MPG, and price per gallon.
Open toolGas Mileage Calculator
Calculate MPG and fuel cost per mile from distance and gallons used.
Open toolMileage Calculator
Calculate mileage reimbursement from business miles and a rate you enter.
Open toolVoltage Drop Calculator
Estimate two-conductor DC or single-phase voltage drop from current and wire resistance.
Open toolHorsepower Calculator
Calculate mechanical horsepower from force and speed.
Open toolEngine Horsepower Calculator
Calculate engine horsepower from torque and RPM.
Open toolStair Calculator
Estimate an even stair count, actual riser height, and horizontal run.
Open toolResistor Calculator
Calculate equivalent resistance for two resistors in series or parallel.
Open toolOhm's Law Calculator
Calculate voltage and power from current and resistance using Ohm's law.
Open toolElectricity Calculator
Estimate appliance energy use and US electricity cost.
Open toolDensity Calculator
Calculate density from mass and volume.
Open toolMass Calculator
Calculate mass from density and volume.
Open toolWeight Calculator
Calculate force of weight from mass and gravitational acceleration.
Open toolSpeed Calculator
Calculate average speed from distance and time.
Open toolMolarity Calculator
Calculate solution molarity from moles and liters.
Open toolMolecular Weight Calculator
Calculate molar mass from a chemical formula, including grouped formulas with parentheses.
Open toolConversion Calculator
Convert common US customary and metric length units.
Open toolPassword Generator
Generate a random password with a selectable character set.
Open toolDice Roller
Roll one or more fair virtual dice with a chosen number of sides.
Open toolIP Subnet Calculator
Calculate an IPv4 network, mask, broadcast address, and usable host range from CIDR prefix length.
Open toolTime Zone Calculator
Convert a date and time between fixed UTC offsets.
Open toolBase64 Encode / Decode
Encode UTF-8 text as Base64 or decode Base64 back to readable text.
Open toolURL Encode / Decode
Encode text as a URL component or decode an encoded component.
Open toolRoman Numeral Converter
Convert whole numbers to standard Roman numerals or Roman numerals to numbers.
Open toolSleep Calculator
Estimate wake or bed times using 90-minute sleep-cycle intervals.
Open toolTire Size Calculator
Calculate tire diameter, sidewall height, circumference, and revolutions per mile.
Open toolRoofing Calculator
Estimate roofing squares and shingle bundles from roof area.
Open toolTile Calculator
Estimate tile quantity from project area, tile dimensions, and waste allowance.
Open toolMulch Calculator
Estimate mulch volume from area and depth.
Open toolGravel Calculator
Estimate gravel volume from area and depth.
Open toolBandwidth Calculator
Estimate ideal file-transfer time from file size and connection speed.
Open toolGDP Calculator
Calculate nominal GDP growth between two values.
Open toolLove Calculator
Create a repeatable, just-for-fun compatibility score from two names.
Open toolBra Size Calculator
Estimate a US starting bra size from snug underbust and full-bust measurements.
Open toolBTU Calculator
Convert power between watts and British thermal units per hour using the DOE conversion factor.
Open toolTime Card Calculator
Total multiple work shifts, unpaid breaks, decimal hours, and estimated gross pay.
Open toolShoe Size Conversion
Estimate adult US men's, US women's, UK, and EU shoe-size equivalents.
Open toolGolf Handicap Calculator
Estimate the unadjusted 8-of-20 Handicap Index calculation from 20 entered Score Differentials.
Open toolWind Chill Calculator
Calculate National Weather Service wind chill from Fahrenheit temperature and wind speed in mph.
Open toolHeat Index Calculator
Calculate the National Weather Service apparent temperature from air temperature and relative humidity.
Open toolDew Point Calculator
Estimate dew point from Fahrenheit temperature and relative humidity using the Magnus equation.
Open toolScientific Calculator
Calculate common trigonometric, logarithmic, root, power, and factorial operations.
Open toolTriangle Calculator
Calculate area, perimeter, and angles from three valid side lengths.
Open toolRight Triangle Calculator
Calculate the hypotenuse, area, perimeter, and acute angles from two legs.
Open toolVolume Calculator
Calculate volume for a cube, rectangular prism, cylinder, cone, or sphere.
Open toolArea Calculator
Calculate area for a rectangle, triangle, circle, parallelogram, or trapezoid.
Open toolSurface Area Calculator
Calculate total surface area for a cube, sphere, cylinder, or rectangular prism.
Open toolRandom Number Generator
Generate one or more uniformly distributed whole numbers in an inclusive range.
Open toolNumber Sequence Calculator
Generate arithmetic or geometric sequences and calculate their sum.
Open toolBinary Calculator
Add, subtract, multiply, or divide two binary whole numbers exactly.
Open toolHex Calculator
Add, subtract, multiply, or divide two hexadecimal whole numbers exactly.
Open toolSample Size Calculator
Estimate a survey sample size for a proportion using confidence level, margin of error, and optional population size.
Open toolProbability Calculator
Calculate an event probability, complement, odds, and percentage from favorable and total outcomes.
Open toolStatistics Calculator
Calculate descriptive population statistics for a list of numbers.
Open toolMean, Median, Mode, Range Calculator
Find mean, median, mode, and range for a list of numbers.
Open toolZ-score Calculator
Calculate how many standard deviations a value lies from a mean.
Open toolConfidence Interval Calculator
Estimate a z-based confidence interval for a mean from sample statistics.
Open toolRatio Calculator
Simplify a ratio of two whole numbers and calculate its decimal value.
Open toolMatrix Calculator
Add, subtract, or multiply two 2 x 2 matrices, or calculate the determinant of matrix A.
Open toolScientific Notation Calculator
Convert a finite decimal number to normalized scientific and engineering notation.
Open toolBig Number Calculator
Add, subtract, or multiply whole numbers up to 500 digits exactly.
Open toolCommon Factor Calculator
List every positive common factor shared by a list of whole numbers.
Open toolLong Division Calculator
Divide two whole numbers and show the integer quotient, remainder, and decimal result.
Open toolP-value Calculator
Calculate a standard-normal p-value from a z statistic and tail selection.
Open toolBMI Calculator
Calculate adult body mass index and the corresponding CDC screening category using US units.
Open toolCalorie Calculator
Estimate adult maintenance calories and cautious example calorie adjustments.
Open toolBody Fat Calculator
Estimate body-fat percentage with the US Navy circumference equations.
Open toolBMR Calculator
Estimate adult resting energy expenditure with the Mifflin-St Jeor equation.
Open toolMacro Calculator
Convert a calorie target and chosen carbohydrate, protein, and fat percentages into grams.
Open toolIdeal Weight Calculator
Compare four historical height-based reference-weight equations for adults.
Open toolPregnancy Calculator
Estimate gestational age and due date from a last menstrual period and an as-of date.
Open toolPregnancy Weight Gain Calculator
Compare current gain with CDC total pregnancy weight-gain ranges for one baby.
Open toolPregnancy Conception Calculator
Estimate conception and last-menstrual-period dates from an established due date.
Open toolDue Date Calculator
Estimate a pregnancy due date from the first day of the last menstrual period and usual cycle length.
Open toolPace Calculator
Calculate running or walking pace and speed from distance and elapsed time.
Open toolArmy Body Composition Calculator
Calculate the current U.S. Army waist-to-height ratio screening measure.
Open toolCarbohydrate Calculator
Convert daily calories and a chosen carbohydrate percentage into grams per day.
Open toolLean Body Mass Calculator
Calculate lean and fat mass from body weight and an entered body-fat percentage.
Open toolHealthy Weight Calculator
Calculate the adult weight range corresponding to the CDC healthy BMI screening range.
Open toolCalories Burned Calculator
Estimate gross exercise calories from body weight, duration, and a MET value you enter.
Open toolOne Rep Max Calculator
Estimate a one-repetition maximum from a submaximal lift using the Epley equation.
Open toolTarget Heart Rate Calculator
Estimate age-predicted maximum heart rate and AHA moderate and vigorous zones.
Open toolProtein Calculator
Convert body weight and a selected grams-per-kilogram factor into daily protein grams.
Open toolFat Intake Calculator
Convert daily calories and a chosen fat percentage into grams per day.
Open toolTDEE Calculator
Estimate total daily energy expenditure from Mifflin-St Jeor resting energy and an activity multiplier.
Open toolOvulation Calculator
Estimate ovulation and a fertile window from a regular cycle.
Open toolConception Calculator
Estimate a calendar fertile window from a regular menstrual cycle.
Open toolPeriod Calculator
Estimate the next two period start dates from a regular cycle.
Open toolGFR Calculator
Estimate adult eGFR with the 2021 race-free CKD-EPI creatinine equation.
Open toolBody Frame Estimate Calculator
Estimate a traditional small, medium, or large body-frame category from height and wrist circumference.
Open toolBody Surface Area Calculator
Estimate body surface area with the Mosteller formula from US height and weight.
Open toolBAC Calculator
Produce a rough Widmark-style blood alcohol concentration estimate from US standard drinks.
Open toolLow BMI Safety Calculator
Calculate adult BMI and identify whether it is below the CDC underweight screening threshold.
Open toolFood Points Total Calculator
Add food point values you already have without reproducing a proprietary points formula.
Open toolOverweight Screening Calculator
Calculate adult BMI and compare weight with the BMI 25 screening threshold.
Open toolInterest Calculator
Calculate compound interest and ending balance with a selected compounding frequency.
Open toolRetirement Calculator
Project retirement savings and compare the result with a selected annual spending goal.
Open toolCurrency Calculator
Convert an amount using an exchange rate you enter, with no stale built-in market quote.
Open toolInflation Calculator
Compare purchasing power using two CPI index values from the same BLS series.
Open toolFinance Calculator
Calculate the future value of a present amount plus regular end-of-month payments.
Open toolMortgage Payoff Calculator
Estimate payoff time and interest from a current mortgage balance, payment, and extra principal.
Open toolIncome Tax Calculator
Estimate 2026 U.S. federal ordinary income tax using published brackets and the larger of standard or entered itemized deductions.
Open toolMarriage Tax Calculator
Compare simplified 2026 federal tax for a joint return with two hypothetical single returns.
Open toolEstate Tax Calculator
Estimate the amount above the 2026 U.S. federal basic estate-tax exclusion and an illustrative 40% tax on that excess.
Open toolHouse Affordability Calculator
Estimate a home price from entered income, debts, down payment, mortgage terms, and housing-cost assumptions.
Open toolRent Calculator
Project total rent paid with an annual increase and optional monthly renter costs.
Open toolPension Calculator
Estimate a defined-benefit pension from final average salary, service years, and a plan multiplier.
Open toolSocial Security Calculator
Estimate the claiming-age adjustment to a monthly primary insurance amount entered by the user.
Open toolAnnuity Calculator
Calculate the future value of equal end-of-month annuity contributions.
Open toolAnnuity Payout Calculator
Calculate a level monthly payout that amortizes a balance over a chosen period and rate.
Open toolCredit Card Calculator
Estimate credit-card payoff time and interest from balance, APR, and a fixed monthly payment.
Open toolCredit Cards Payoff Calculator
Estimate combined payoff results for multiple cards when each keeps its entered fixed payment.
Open toolDebt Payoff Calculator
Estimate payoff for a combined debt balance using a blended APR, required payment, and extra monthly amount.
Open toolDebt Consolidation Calculator
Compare current combined debt payoff with a proposed fixed-rate consolidation loan.
Open toolRepayment Calculator
Estimate how long a fixed monthly payment takes to repay an interest-bearing balance.
Open toolStudent Loan Calculator
Calculate a standard fixed-payment student-loan repayment estimate.
Open toolCollege Cost Calculator
Project a multi-year college cost from current annual cost, inflation, years until enrollment, and attendance length.
Open toolCD Calculator
Calculate certificate-of-deposit maturity value and interest from APY.
Open toolBond Calculator
Price a fixed-rate coupon bond from face value, coupon rate, yield, maturity, and payment frequency.
Open toolMutual Fund Calculator
Project mutual-fund value using an expected gross return minus an entered expense ratio.
Open tool401(k) Calculator
Project a 401(k) with employee deferrals, employer match, returns, and 2026 age-based deferral limits.
Open toolRoth IRA Calculator
Estimate a 2026 Roth IRA contribution limit from filing status and MAGI, then project account growth.
Open toolIRA Calculator
Project an IRA using an entered annual contribution and the 2026 age-based contribution limit.
Open toolRMD Calculator
Calculate an owner RMD with the IRS Uniform Lifetime Table for ages 73 through 120 or older.
Open toolCash Back or Low Interest Calculator
Compare a cash-back card with a lower-rate card over a chosen fixed payoff period.
Open toolAuto Lease Calculator
Estimate a U.S. auto lease payment from adjusted capitalized cost, residual, money factor, term, and sales tax.
Open toolReal Estate Calculator
Estimate investment profit and return from purchase, sale, income, expenses, and transaction costs.
Open toolTake-Home Paycheck Calculator
Estimate 2026 U.S. take-home pay using simplified federal brackets, employee payroll taxes, entered pre-tax deductions, and an entered state/local rate.
Open toolLease Calculator
Estimate a generic level lease payment from asset cost, residual value, annual financing rate, and term.
Open toolRefinance Calculator
Compare current and proposed fixed mortgage payments, interest, costs, and simple break-even time.
Open toolBudget Calculator
Summarize a monthly budget and calculate remaining cash flow and savings rate.
Open toolRental Property Calculator
Estimate monthly cash flow, net operating income, and cap rate for a financed rental property.
Open toolIRR Calculator
Estimate an internal rate of return for periodic cash flows using numerical root finding.
Open toolAPR Calculator
Estimate a nominal annual percentage rate from amount financed after fees, payment, and number of monthly payments.
Open toolFHA Loan Calculator
Estimate an FHA payment using entered price, down payment, rate, term, 1.75% upfront MIP, and entered annual MIP rate.
Open toolVA Mortgage Calculator
Estimate a VA purchase-loan payment with current published funding-fee categories and an exemption option.
Open toolHome Equity Loan Calculator
Calculate payment and interest for a fixed-rate home equity loan.
Open toolHELOC Calculator
Estimate interest-only and amortizing payments for a home equity line balance.
Open toolRent vs. Buy Calculator
Compare projected renter cost with simplified homeowner cost and equity over a chosen period.
Open toolMortgage Calculator UK
Calculate a standard UK-style capital-and-interest monthly mortgage payment in pounds.
Open toolCanadian Mortgage Calculator
Calculate a Canadian mortgage payment using a nominal annual rate compounded semi-annually and a selected payment frequency.
Open toolMortgage Amortization Calculator
Calculate fixed mortgage payment totals and first-payment principal and interest allocation.
Open toolPercent Off Calculator
Calculate sale price, savings, and optional sales tax from an original price and percent-off discount.
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