Free Online Calculators
137+ calculators for finance, health, math, conversions, and everyday life. Fast, accurate, and completely free.
Mortgage Calculator Calculate your monthly mortgage payment including principal, interest, taxes, an
Loan Calculator Calculate monthly loan payments, total interest, and total cost for any personal
Compound Interest Calculator Calculate compound interest with monthly contributions. See how your money grows
Savings Calculator Calculate how much your savings will grow with regular monthly deposits. See you
Investment Calculator Calculate the future value of investments with monthly contributions. See how mu
Auto Loan Calculator Calculate your monthly car payment, total interest, and total cost for any auto
Retirement Calculator Calculate your retirement savings balance and estimated monthly income. See how
Salary Calculator Convert annual salary to hourly, daily, weekly, bi-weekly, and monthly pay. Inst
Paycheck Calculator Estimate your take-home pay after federal taxes, state taxes, FICA, and deductio
Tip Calculator Calculate tip amount and total bill instantly. Split the bill between multiple p
Amortization Calculator Calculate monthly loan payments and total interest for any amortizing loan. See
Interest Calculator Calculate compound interest earned on any principal amount. Compare simple vs co
Down Payment Calculator Calculate how much you need for a down payment on a home. See total cash needed
Debt Payoff Calculator Calculate how long it takes to pay off debt and total interest paid. See your de
Credit Card Payoff Calculator Calculate how long to pay off credit card debt and total interest cost. See the
Savings Goal Calculator Calculate how long it takes to reach your savings goal. Enter your target amount
Income Tax Calculator Estimate your 2024–2025 federal income tax using current tax brackets. See your
Sales Tax Calculator Calculate sales tax amount and total price with tax. Also reverse-calculate the
Inflation Calculator Calculate the future value of money adjusted for inflation. See how inflation er
Net Worth Calculator Calculate your net worth by adding up all assets and subtracting all liabilities
Budget Calculator Calculate your monthly budget surplus or deficit. Track income vs expenses acros
ROI Calculator Calculate return on investment (ROI) percentage, net profit, and annualized ROI
Simple Interest Calculator Calculate simple interest using the I = P × R × T formula. Find interest earned
Hourly to Salary Calculator Convert hourly wage to annual salary. Calculate yearly, monthly, bi-weekly, and
Rent vs Buy Calculator Compare the true cost of renting vs buying a home over your time horizon. Includ
BMI Calculator Calculate your Body Mass Index (BMI) using weight and height. See your BMI categ
Calorie Calculator Calculate daily calorie needs based on age, gender, weight, height, and activity
Body Fat Calculator Calculate body fat percentage using the U.S. Navy method with waist, neck, and h
BMR Calculator Calculate your Basal Metabolic Rate using both Mifflin-St Jeor and Harris-Benedi
TDEE Calculator Calculate Total Daily Energy Expenditure based on BMR and activity level. Find y
Macro Calculator Calculate daily macronutrient targets — protein, carbs, and fat grams — based on
Ideal Weight Calculator Calculate your ideal body weight using Devine, Robinson, Miller, and Hamwi formu
Protein Calculator Calculate how much protein you need per day based on weight and fitness goals.
Pregnancy Calculator Calculate your due date, current trimester, and weeks pregnant based on your las
Due Date Calculator Calculate your baby's due date from last menstrual period or conception date. Se
Ovulation Calculator Calculate your ovulation date and fertile window based on your menstrual cycle l
Sleep Calculator Calculate optimal bedtimes based on your wake-up time and 90-minute sleep cycles
Water Intake Calculator Calculate how much water you should drink daily based on weight, activity level,
Heart Rate Calculator Calculate maximum heart rate and target training zones using the Karvonen method
Pace Calculator Calculate running or walking pace, speed, and predicted finish times from your d
Calories Burned Calculator Calculate calories burned during exercise based on activity type, duration, and
BAC Calculator Estimate blood alcohol content based on drinks consumed, body weight, gender, an
One Rep Max Calculator Estimate your one-rep max (1RM) from weight lifted and reps completed. See train
Percentage Calculator Calculate percentages instantly. Find X% of a number, what percent X is of Y, an
Fraction Calculator Add, subtract, multiply, and divide fractions. Get results as simplified fractio
Scientific Calculator Online scientific calculator supporting trigonometry, logarithms, square roots,
GPA Calculator Calculate your GPA from letter grades and credit hours. Supports A through F gra
Grade Calculator Find out what score you need on your final exam to achieve your desired course g
Average Calculator Calculate the mean, median, and mode of any set of numbers. Enter comma-separate
Standard Deviation Calculator Calculate population or sample standard deviation and variance for any data set.
Random Number Generator Generate random numbers between any min and max. Choose how many numbers and dec
Square Root Calculator Calculate the square root, cube root, and fourth root of any number. Instantly c
Exponent Calculator Calculate any base raised to any exponent. See results in standard and scientifi
Logarithm Calculator Calculate log base 10, natural log (ln), log base 2, or any custom base logarith
Quadratic Formula Calculator Solve quadratic equations ax²+bx+c=0 using the quadratic formula. Find roots, di
Triangle Calculator Calculate triangle area, perimeter, and all three angles from the three side len
Pythagorean Theorem Calculator Calculate hypotenuse or missing leg using the Pythagorean theorem a²+b²=c². Find
GCD & LCM Calculator Calculate the Greatest Common Divisor (GCD) and Least Common Multiple (LCM) of t
Long Division Calculator Perform long division and find the quotient, remainder, and decimal result for a
Mixed Number Calculator Add, subtract, multiply, and divide mixed numbers. Get results as mixed numbers,
Probability Calculator Calculate probability, odds in favor, odds against, and complementary probabilit
Variance Calculator Calculate population variance (σ²) or sample variance (s²) for any data set. Als
Matrix Calculator Calculate the determinant, inverse, and matrix multiplication for 2×2 and 3×3 ma
Temperature Converter Convert temperature between Celsius, Fahrenheit, and Kelvin instantly. Free onli
Length Converter Convert length and distance between metric and imperial units. Supports mm, cm,
Weight Converter Convert weight and mass between kilograms, pounds, ounces, grams, stone, and met
Volume Converter Convert volume between milliliters, liters, US gallons, quarts, pints, cups, flu
Area Converter Convert area between square feet, square meters, acres, hectares, square yards,
Speed Converter Convert speed between miles per hour, kilometers per hour, meters per second, kn
Hex to Decimal Converter Convert hexadecimal numbers to decimal, binary, and octal instantly. Essential t
Binary to Decimal Converter Convert binary numbers to decimal, hexadecimal, and octal. Supports any binary i
Cups to Grams Converter Convert cups to grams for flour, sugar, butter, and other ingredients. Accurate
Feet and Inches to Meters Converter Convert feet and inches to meters and centimeters. Perfect for height conversion
Celsius to Fahrenheit Converter Convert Celsius to Fahrenheit and Kelvin instantly. Simple °C to °F conversion t
Inches to Centimeters Converter Convert inches to centimeters, millimeters, and meters instantly. Fast and accur
Ounces to Grams Converter Convert ounces to grams, kilograms, and pounds instantly. Accurate oz to g conve
Pounds to Kilograms Converter Convert pounds to kilograms, grams, and stone. Fast lbs to kg converter for body
Miles to Kilometers Converter Convert miles to kilometers, meters, and feet instantly. Accurate mi to km conve
Color Code Converter Convert color codes between HEX, RGB, and HSL formats. Essential tool for web de
Age Calculator Calculate your exact age in years, months, and days from your birth date. Find o
Date Calculator Add or subtract days, months, and years from any date. Find what date it will be
Time Calculator Add or subtract hours and minutes from any time of day. Great for scheduling, sh
Hours Calculator Calculate the number of hours and minutes worked between a start time and end ti
Days Between Dates Calculator Find the exact number of days, weeks, and months between two dates. Useful for p
Time Zone Converter Convert a time from one time zone to another. Supports UTC offsets for all major
Countdown Calculator Find out exactly how many days, hours, and minutes remain until any future date.
Work Hours Calculator Calculate net daily work hours from start time, end time, and break. Extrapolate
Time Duration Calculator Convert a duration in hours, minutes, and seconds into total seconds, decimal ho
Unix Timestamp Converter Convert a Unix epoch timestamp to a human-readable date, or convert a date to a
Concrete Calculator Calculate how much concrete you need in cubic yards and cubic meters, plus the n
Square Footage Calculator Calculate the area of a rectangular space in square feet, square meters, and acr
Paint Calculator Calculate how many gallons of paint you need for a room. Accounts for walls, cei
Tile Calculator Calculate the number of tiles needed for a floor or wall. Includes waste percent
Flooring Calculator Calculate how much flooring you need in square feet, including a waste percentag
Roofing Calculator Calculate how many roofing squares, shingle bundles, and sheets of underlayment
Mulch Calculator Calculate cubic yards and cubic feet of mulch needed for any garden bed or lands
Gravel Calculator Calculate how many tons and cubic yards of gravel, crushed stone, or pea gravel
Fence Calculator Calculate how many fence posts, rails, and boards you need for any fencing proje
Deck Calculator Estimate deck boards, joists, and support posts needed for a deck based on dimen
Drywall Calculator Calculate how many sheets of drywall (4×8 or 4×12) you need for walls and ceilin
Wallpaper Calculator Calculate how many rolls of wallpaper you need for a room, accounting for patter
Insulation Calculator Calculate how many batts or rolls of insulation you need for walls, attics, or c
Ohm's Law Calculator Calculate voltage, current, or resistance using Ohm's Law. Enter any two values
Voltage Calculator Calculate electrical voltage from current and resistance, or from power and curr
Resistor Color Code Calculator Decode resistor color bands to find resistance value and tolerance. Supports 4-b
Speed Calculator Calculate speed from distance and time, distance from speed and time, or time fr
Density Calculator Calculate density from mass and volume, mass from density and volume, or volume
Force Calculator Calculate force, mass, or acceleration using Newton's Second Law F = ma. Support
Molar Mass Calculator Find the molar mass of common elements and chemical compounds in g/mol. Instantl
pH Calculator Calculate pH from hydrogen ion concentration [H⁺], or find [H⁺] and [OH⁻] from a
Half-Life Calculator Calculate the remaining amount of a radioactive substance after a given time usi
Profit Margin Calculator Calculate gross profit margin percentage and gross profit from revenue and cost.
Markup Calculator Calculate selling price and profit from cost and markup percentage. Understand t
Break-Even Calculator Find how many units you need to sell to cover all costs. Calculate your break-ev
VAT Calculator Add or remove VAT from any price. Calculate VAT amount and total price inclusive
Discount Calculator Quickly calculate the sale price and how much you save with any discount percent
Commission Calculator Calculate commission earned from a sale. Add base salary to find total compensat
Freelance Rate Calculator Calculate the minimum hourly rate you need to charge as a freelancer to hit your
Invoice Calculator Calculate invoice totals with multiple line items, tax, and optional discounts.
Hourly Rate Calculator Convert annual salary to hourly, daily, and monthly rates. See what your $60k, $
Depreciation Calculator Calculate annual asset depreciation using straight-line or double-declining bala
Gas Mileage Calculator Calculate your car's fuel economy in MPG and cost per mile. Track fuel efficienc
Fuel Cost Calculator Estimate the total fuel cost for any road trip. Enter distance, MPG, and gas pri
Electricity Cost Calculator Calculate how much any appliance or device costs to run. Find daily, monthly, an
Dog Age Calculator Convert your dog's age to human years by breed size. The modern formula accounts
Snow Day Calculator Estimate the probability of a snow day school closure based on forecasted snowfa
Dice Roller Roll virtual dice for tabletop RPGs, board games, and decisions. Supports D4, D6
Password Generator Generate strong, random passwords with custom length and character sets. Calcula
Subnet Calculator Calculate network address, broadcast address, subnet mask, and number of usable
Random Name Picker Pick random winners or entries from a list. Select one or multiple names fairly
Sleep Quality Calculator Calculate your sleep quality score, total sleep time, and number of sleep cycles
Bra Size Calculator Find your correct bra size in US and UK sizing from your band and bust measureme
Carbon Footprint Calculator Calculate your annual carbon footprint from driving, flights, and home energy us
Coin Flip Flip a virtual coin online. Simulate single or multiple coin tosses with fair 50
Tip Split Calculator Split a restaurant bill with tip among friends. Calculate each person's share wi
Age Difference Calculator Calculate the age difference between two people in years, months, and days.
Screen Time Calculator Calculate your total daily screen time across devices. See weekly and yearly tot