Browse 153 free tools. Every calculator works in your browser and requires no account.
Add or subtract a chosen number of calendar days from any date.
Calculate age in years, months and days from a birth date to a selected date.
Calculate a fixed-rate loan payment and view how principal and interest change through an amortization schedule.
Convert hourly, weekly, biweekly, semimonthly or monthly gross pay into an estimated annual income.
Convert a stated interest rate and compounding frequency into annual percentage yield (APY).
Convert area between square feet, square meters, acres, hectares, square miles and other common units.
Estimate asphalt volume and tons from area, compacted depth and material density.
Estimate an auto loan payment after down payment, trade-in and sales tax.
Find the arithmetic mean of a comma-separated list of numbers.
Compare a standard monthly mortgage schedule with an accelerated biweekly payment approach.
Estimate body mass index from height and weight using the standard adult BMI formula.
Estimate basal metabolic rate using the Mifflin–St Jeor equation.
Calculate lumber board feet from thickness, width, length and quantity.
Estimate body surface area using the Mosteller formula.
Find the number of units needed to cover fixed costs using price and variable cost per unit.
Estimate the number of bricks needed for a wall from wall area, brick dimensions, mortar joint and waste.
Count weekdays between two dates, excluding Saturdays and Sundays.
Calculate compound annual growth rate between a beginning value and ending value over a number of years.
Estimate daily calorie needs by multiplying estimated BMR by an activity factor.
Estimate the maturity value and interest earned on a certificate of deposit using APY and term length.
Convert Celsius temperatures to Fahrenheit.
Calculate circumference and area from a circle radius.
Find the average, highest and lowest score from a list of class or assignment scores.
Convert centimeters to inches.
Calculate combinations nCr: the number of ways to choose r items from n when order does not matter.
Calculate commission and total pay from sales, commission rate and optional base pay.
Project how money grows when interest is added to the balance and earns interest over time.
Estimate concrete masonry units (CMU) needed for a wall from wall dimensions, block face size and waste.
Estimate cubic yards of concrete for a rectangular slab and add an optional waste allowance.
Calculate cone volume, slant height and total surface area from radius and vertical height.
Calculate conversion rate from conversions and total visitors, sessions, leads or clicks.
Calculate cost per acquisition (CPA) from campaign spend and acquired customers or conversions.
Calculate cost per square foot or total project cost from area and total price.
Calculate advertising cost per click (CPC) from total ad spend and clicks.
Calculate cost per thousand impressions (CPM) from ad spend and impressions.
Estimate how long a credit-card balance takes to pay off with a fixed monthly payment, assuming no new charges.
Calculate click-through rate (CTR) from clicks and impressions.
Calculate cubic feet and cubic yards from length, width and height measurements.
Convert rectangular dimensions in feet to cubic yards for soil, gravel, concrete and landscaping materials.
Convert US customary cups to milliliters.
Calculate customer acquisition cost by dividing acquisition spending by new customers gained.
Estimate simple customer lifetime value (CLV) from average order value, purchase frequency, gross margin and customer lifespan.
Calculate the volume and total surface area of a right circular cylinder.
Convert digital storage between bytes, kilobytes, megabytes, gigabytes and terabytes using decimal units.
Find the weekday for any valid calendar date.
Count the number of calendar days between two dates.
Count calendar days from a starting date to a future or past target date.
Estimate payoff time and interest for a debt when you make a fixed monthly payment.
Calculate your debt-to-income ratio by comparing monthly debt payments with gross monthly income.
Convert decimal hours to hours and minutes.
Convert a terminating decimal to a reduced fraction and mixed number.
Estimate deck area and project cost from deck dimensions, cost per square foot and a contingency percentage.
Calculate a sale price, amount saved and optional final price after sales tax.
Calculate straight-line distance between two points on a 2D coordinate plane.
Estimate drywall sheet count from wall dimensions, room count, sheet size and waste allowance.
Convert energy between joules, kilojoules, calories, kilocalories, watt-hours and kilowatt-hours.
Convert Fahrenheit temperatures to Celsius.
Estimate fence pickets from fence length, picket width and gap between pickets.
Find the score needed on a final exam to reach a desired overall course grade.
Estimate flooring area and purchase quantity with a waste allowance.
Add, subtract, multiply or divide two fractions and reduce the result to lowest terms.
Convert vehicle fuel economy between miles per gallon (U.S.) and liters per 100 kilometers.
Find the future value of a present amount after a chosen rate of return and time period.
Convert US liquid gallons to liters.
Find the greatest common factor (greatest common divisor) of two or more whole numbers.
Calculate an unweighted GPA from up to six course grades and credit hours on a standard 4.0 scale.
Calculate a current course percentage from points earned and points possible.
Estimate cubic yards and approximate tons of gravel from area and depth.
Estimate grout volume from tile size, joint width, joint depth and tiled area.
Estimate a home price range from income, monthly debts, down payment, mortgage rate and a target debt-to-income ratio.
Convert an hourly wage to estimated weekly, monthly and annual gross pay.
Convert hours and minutes into decimal hours for timesheets and payroll calculations.
Find elapsed hours and minutes between two clock times, including overnight intervals.
Convert inches to centimeters.
Calculate inventory turnover and approximate days inventory on hand from cost of goods sold and average inventory.
Calculate investment gain, total return and annualized return from a beginning value, ending value and holding period.
Convert kilograms to pounds.
Calculate total lawn area from up to four rectangular sections and convert square feet to acres.
Find the least common multiple of two or more whole numbers.
Convert length between inches, feet, yards, miles, millimeters, centimeters, meters and kilometers.
Calculate the payment and total interest for a standard installment loan with equal monthly payments.
Calculate gross margin percentage and profit dollars from cost and selling price.
Calculate selling price and markup percentage from an item cost and desired markup.
Find the mean, median, mode and range of a list of numbers.
Find the midpoint between two points on a coordinate plane.
Calculate completed calendar months plus remaining days between two dates.
Estimate a fixed-rate mortgage payment, total interest and total of payments from the loan amount, interest rate and term.
Estimate how an extra monthly payment can shorten a mortgage payoff timeline and reduce interest.
Estimate cubic yards of mulch from bed area and desired depth.
Find the cumulative probability below, above or between values in a normal distribution.
Estimate weekly gross pay from regular hours, overtime hours, hourly rate and an overtime multiplier.
Estimate gallons of wall paint from room dimensions, wall height, coats and paint coverage.
Estimate paver count from project area, paver size and waste allowance.
Calculate a new salary or wage, dollar increase and approximate monthly increase from a percentage raise.
Calculate percentage increase or decrease from an original value to a new value.
Calculate symmetric percent difference between two values without treating either one as the original value.
Calculate percent error between an experimental or measured value and an accepted value.
Solve common percentage questions: find a percentage of a number, determine what percent one number is of another, and calculate a value from a known percentage.
Calculate permutations nPr: the number of ordered arrangements of r items chosen from n.
Estimate rectangular pool water volume in gallons from length, width and average depth.
Convert pounds to kilograms.
Discount a future amount back to its value today using a selected annual discount rate.
Convert pressure between psi, pascals, kilopascals, bar and atmospheres.
Break a positive whole number into its prime factors.
Calculate the probability of one event, its complement, and simple independent AND/OR combinations.
Calculate net profit, profit margin and revenue retained after expenses.
Solve a proportion of the form a/b = c/d when one of the four values is unknown.
Find the hypotenuse of a right triangle from the two perpendicular side lengths.
Solve a quadratic equation in the form ax² + bx + c = 0 and identify real or complex roots.
Simplify a ratio of two whole numbers to lowest terms.
Calculate area, perimeter and diagonal of a rectangle from length and width.
Estimate monthly savings, closing-cost break-even time and interest difference when refinancing a loan.
Compare estimated housing cost over a chosen period for renting versus buying a home.
Find the average needed on remaining coursework to reach a target overall grade.
Solve a right triangle from two side lengths and find the hypotenuse, angles, area and perimeter.
Calculate return on ad spend from advertising-attributed revenue and ad cost.
Calculate return on investment from an initial cost and the amount received or current value.
Estimate roofing squares and bundles from roof area and waste percentage.
Calculate average running pace and speed from distance and elapsed time.
Convert annual salary to an estimated hourly rate from weekly hours and weeks worked per year.
Calculate sales growth or decline from a prior-period sales amount to a current-period amount.
Calculate sales tax and the final purchase total from a pre-tax price and tax rate.
Estimate sand volume and approximate weight from project dimensions and material density.
Estimate the future value of savings with an initial balance, regular monthly contributions and compound interest.
Convert a number to normalized scientific notation and evaluate a coefficient times a power of ten.
Estimate siding square footage and squares from exterior wall dimensions, openings and waste.
Calculate interest earned or charged when interest is applied only to the original principal.
Find the slope of the line through two coordinate points.
Convert speed between miles per hour, kilometers per hour, meters per second and knots.
Calculate the volume and surface area of a sphere from its radius.
Calculate rectangular area in square feet from length and width measurements in feet.
Estimate stair riser count, actual riser height and tread run from total rise and target riser height.
Calculate mean, variance and standard deviation for a sample or an entire population.
Estimate the monthly payment, total repayment and total interest on a fixed-rate student loan.
Estimate exercise heart-rate zones from age using a simple percentage of estimated maximum heart rate.
Convert temperature between Fahrenheit, Celsius and Kelvin.
Convert correct answers and total questions into a test percentage.
Estimate the number of rectangular tiles needed for a floor or wall area, including waste.
Calculate weekly work hours and gross pay from daily clock-in, clock-out and unpaid break times.
Find elapsed time between a start time and end time, including overnight periods.
Calculate a tip, total bill and per-person amount when splitting a restaurant or service bill.
Estimate cubic yards of topsoil from area and desired depth.
Calculate triangle area using a base and perpendicular height.
Convert volume between U.S. gallons, quarts, pints, cups, fluid ounces, liters and milliliters.
Calculate waist-to-height ratio using waist circumference and height in the same units.
Calculate walking pace and speed from distance and elapsed time.
Estimate wallpaper rolls from wall area, roll coverage and waste allowance.
Convert the calendar-day difference between two dates into weeks and remaining days.
Convert weight and mass between ounces, pounds, stones, grams, kilograms and metric tonnes.
Estimate GPA when honors or AP/IB courses receive extra grade-point weight.
Calculate a weighted course average from four category scores and weights.
Calculate paid work hours from start time, end time and an unpaid break.
Calculate a z-score from a value, mean and standard deviation.