150+ Free Online Calculators, All in One Place

Estimate monthly mortgage payments, total interest and amortization for any home loan amount, rate and term.

Work out the monthly repayment, total interest and total cost of any personal, auto or student loan.

See how your savings grow with compound interest. Add monthly contributions and choose any compounding frequency.

Calculate simple interest, total amount and interest earned over any period.

Find out how much you need to save each month to reach a financial goal by a target date.

Project your retirement savings using current age, retirement age, savings, monthly contributions and expected return.

See how inflation erodes the purchasing power of money over time.

Add sales tax to a price, or work backwards from a tax-included price to find the pre-tax amount.

Calculate the sale price after a percentage discount and see how much you save.

Calculate return on investment (ROI), profit and annualized return.

Convert between hourly, weekly, monthly and annual pay.

Estimate your take-home pay after a flat tax rate. Adjustable pay frequency and pre-tax deductions.

Quickly compute tips and split a bill between any number of people, with optional tax handling.

Convert between currencies using a rate you supply (no live data — works offline).

See how long it will take to pay off a credit card balance and how much interest you will pay.

Calculate your monthly auto loan payment including down payment, trade-in value and sales tax.

Estimate your US federal income tax using 2024 brackets for single, married-jointly and head-of-household filers.

Quickly compare the monthly cost of renting versus buying a home.

Split your monthly income into needs, wants and savings using the popular 50/30/20 budget rule.

See how mutual fund or ETF expense ratios eat into your returns over decades.

Calculate the maturity value and interest earned on a Certificate of Deposit (CD).

Find the number of units you need to sell to cover fixed and variable costs.

Calculate the selling price, profit and margin from a cost and markup percentage.

Add up your assets and liabilities to find your current net worth.

Compare two loan offers side-by-side: monthly payment, total interest and total cost.

See whether refinancing your mortgage is worth it: monthly savings, total savings and break-even point.

See how much interest you save and how many years you cut by adding extra to your monthly mortgage payment.

Compare the total cost of leasing vs buying a car over the same period, including residual value and interest.

Calculate gain or loss on a stock trade including buy/sell commissions, plus % return and break-even price.

Calculate weekly pay including overtime hours at time-and-a-half (or any custom multiplier).

Convert between APR (nominal) and APY (effective annual yield) for any compounding frequency.

Find how big your emergency fund should be and how long it will take to reach it.

Calculate dividend yield, annual dividend income and projected reinvestment returns (DRIP).

Calculate the monthly payout an annuity will deliver for a given principal, rate and number of years.

Compare the after-tax future value of a Roth IRA vs a Traditional IRA contribution given current and retirement tax rates.

Find the maximum home price you can afford based on income, debts, down payment and interest rate using the 28/36 rule.

Calculate the capitalization rate (cap rate) of a rental property: NOI ÷ property value.

Estimate your Financial Independence / Retire Early (FIRE) number using the 25× rule and a custom safe withdrawal rate.

Calculate gain or loss on a crypto trade including buy/sell exchange fees and percentage return.

Calculate the monthly payment, total interest and effective APR of a business loan including origination fees.

Calculate your Body Mass Index (BMI) instantly using metric or imperial units. Understand whether your weight is healthy for your height.

Estimate your Basal Metabolic Rate (BMR) and daily calorie needs (TDEE) using the Mifflin–St Jeor equation.

Estimate your body fat percentage using the U.S. Navy circumference method.

Find your ideal body weight using the Devine and Robinson formulas.

Estimate how much water you should drink each day based on your weight and activity level.

Split your daily calorie target into protein, carbohydrate and fat grams based on your goal.

Estimate your due date and current week of pregnancy from your last menstrual period.

Find your maximum heart rate and the five common training zones from your age.

Calculate running pace, time or distance — fill any two and we work out the third.

Estimate your one-rep max (1RM) for any lift using the Epley formula.

Find optimal bedtimes or wake-up times based on 90-minute sleep cycles.

Estimate your lean body mass using the Boer formula from height, weight and gender.

Calculate your waist-to-hip ratio (WHR) and see your associated health risk category.

Calculate body surface area (BSA) using the Mosteller and Du Bois formulas — used in clinical dosing.

Estimate your most fertile days and next period from your last menstrual period and cycle length.

Estimate calories burned during exercise from activity type, duration and your weight.

Find your daily protein target in grams based on weight and activity goal.

Estimate blood alcohol content (BAC) using the Widmark formula — for educational use only.

Find what daily calorie deficit will get you to your goal weight by a target date.

Convert step count to distance and calories burned using your height.

Estimate your VO₂ max from a 1.5-mile run time using the Cooper formula.

Estimate your baby's due date and current pregnancy week from your last menstrual period (LMP) and cycle length.

Estimate the most likely date of conception from a known due date or last menstrual period.

Estimate the daily formula intake and per-feeding amount based on your baby's weight and age.

Predict a child's adult height using the mid-parental height (Tanner) formula.

Predict your marathon, half-marathon or 10K finish time from a recent race using Riegel's formula.

Plan your intermittent fasting window — 16:8, 18:6, 20:4 or OMAD — and see your eating window times.

Calculate your 5 heart-rate training zones (recovery, endurance, tempo, threshold, VO₂) using the Karvonen method.

Calculate your Total Daily Energy Expenditure (TDEE) from BMR and activity level using the Mifflin–St Jeor equation.

Compare your push-up count against age- and gender-based fitness norms (excellent / good / average / poor).

Calculate your swim pace per 100 m or per 100 yd from a known swim distance and finish time.

Calculate your cycling power-to-weight ratio (W/kg) at FTP and see your category from untrained to world-class.

Calculate your total cholesterol-to-HDL ratio and LDL-to-HDL ratio with cardiovascular risk categories.

Classify a blood pressure reading by AHA categories: normal, elevated, hypertension stage 1 / 2, or crisis.

Calculate your waist-to-height ratio (WHtR) — a strong predictor of cardiovascular and metabolic risk.

Determine your body shape (hourglass, pear, apple, rectangle, inverted triangle) from bust, waist and hip measurements.

Track your weekly sleep debt by comparing actual sleep against your target nightly hours.

Calculate your Wilks score for powerlifting to compare lifters across body weights and genders.

Calculate percentages, percentage of a number, percentage change and reverse percentages — all in one place.

A safe scientific calculator that evaluates arithmetic expressions with sin, cos, tan, log, sqrt, π, e and more.

Add, subtract, multiply or divide two fractions. Result is shown in lowest terms.

Calculate square roots and nth roots of any non-negative number.

Solve any quadratic equation. Real and complex roots, plus the discriminant.

Find the greatest common divisor (GCD) and least common multiple (LCM) of any list of integers.

Solve a right triangle — give any two sides and get the third side, area and perimeter.

Calculate the area, diameter or circumference of a circle from any one of those values.

Calculate the volume of a cube, sphere or cylinder.

Calculate the probability of independent events occurring together or either occurring.

Generate one or many random integers in any range, with or without duplicates.

Calculate logarithms with any base, including ln (natural log) and log base 10.

Raise any number to any real-number power, including negative and fractional exponents.

Compute the factorial of any non-negative integer up to 170 (and big-integer for higher values).

Compute combinations (nCr) and permutations (nPr) for any non-negative integers n ≥ r.

Calculate the determinant, inverse and transpose of a 2×2 matrix.

Find the straight-line distance and midpoint between two points on a 2D plane.

Find the slope, y-intercept and equation of the line passing through two points.

Calculate the mean, median, mode and range of any list of numbers.

Calculate the population and sample standard deviation, variance and mean of a data set.

Convert numbers between binary, octal, decimal and hexadecimal bases.

Calculate the percentage change (increase or decrease) between two numbers.

Simplify a ratio to lowest terms or solve a proportion A:B = C:D for the missing value.

Find the prime factorization of any positive integer up to 10¹⁵ using trial division.

Find the nth term and partial sum of an arithmetic sequence given the first term and common difference.

Find the nth term and partial sum of a geometric sequence given the first term and common ratio.

Solve a 2×2 system of linear equations a₁x + b₁y = c₁ using Cramer's rule.

Add, subtract, multiply or divide two complex numbers and view the result in rectangular and polar form.

Compute binomial probabilities P(X=k), P(X≤k) and P(X≥k) for n trials with success probability p.

Convert a raw score to a z-score and find the corresponding percentile for a normal distribution.

Calculate the confidence interval for a sample mean given sample size, mean, standard deviation and confidence level.

Calculate the probability of rolling a given sum (or range) when rolling any number of fair dice.

Compute the nth Fibonacci number (using BigInt) and list the first n Fibonacci numbers in the sequence.

Find your exact age in years, months, weeks and days from your date of birth to any target date.

Find the exact number of days, weeks, months and years between any two dates.

Add or subtract hours, minutes and seconds from a starting time.

See the time in another time zone given an offset from UTC.

Convert between meters, feet, inches, centimeters, kilometers, miles and yards.

Convert between kilograms, pounds, ounces, grams and stones.

Convert temperatures between Celsius, Fahrenheit and Kelvin.

Convert between kilometers per hour, miles per hour, meters per second and knots.

Estimate the fuel cost of a trip from distance, fuel economy and fuel price.

Calculate your weighted Grade Point Average from any list of grades and credits.

Find your test percentage and letter grade from the number of correct and total questions.

Generate strong random passwords with custom length and character set.

Count words, characters (with and without spaces), sentences and reading time of any text.

Convert between square meters, square feet, acres, hectares and other area units.

Convert between liters, gallons, milliliters, cups, pints, quarts and fluid ounces.

Convert between bytes, kilobytes, megabytes, gigabytes and terabytes (binary or decimal).

Convert between cups, tablespoons, teaspoons, milliliters and fluid ounces — perfect for the kitchen.

Convert shoe sizes between US, UK and EU systems for men and women.

Convert between Arabic numbers and Roman numerals (1 to 3999).

Convert text between UPPERCASE, lowercase, Title Case, Sentence case, camelCase, snake_case and kebab-case.

Encode text to Base64 or decode Base64 back to plain UTF-8 text.

Convert between Unix timestamps (seconds since 1970) and human-readable dates.

Generate one or more random UUID v4 identifiers using the browser's crypto API.

Calculate the exact age difference between two people in years, months and days.

Convert your dog's age into human years using a modern size-aware formula (small / medium / large breeds).

Estimate how much paint you need for a room based on wall dimensions, doors, windows and number of coats.

Calculate the cubic yards or cubic meters of concrete and number of bags needed for a slab, footing or column.

Calculate how many tiles you need for a floor or wall, including a waste percentage for cuts.

Estimate the running cost of any electrical appliance per day, month and year based on wattage and usage hours.

Convert colors between HEX, RGB and HSL formats with a live preview swatch.

Calculate the great-circle distance between two latitude/longitude coordinates using the Haversine formula.

Calculate the wind chill temperature — how cold it really feels — from temperature and wind speed (NWS formula).

Calculate the heat index (apparent temperature) from temperature and relative humidity using the NWS Rothfusz regression.

Calculate the dew point temperature from air temperature and relative humidity using the Magnus formula.

Calculate the tip on a restaurant bill and split the total fairly across any number of people.

Find the exact years, months, days, hours and minutes remaining until a future date and time.

Find your Western (Aries, Taurus…) and Chinese (Rat, Ox…) zodiac signs from your date of birth.

Estimate the years you may have left and your life expectancy using current age, sex and US actuarial baselines.

Resize an image or video to a target width or height while preserving its aspect ratio.