Free Online Calculators & Tools
Fast, accurate calculators, converters, and text tools. No signup required. Use them instantly in your browser.
Calculators
Math, finance, and everyday calculators
Percentage Calculator
Calculate percentages instantly. Find what percent one number is of another, percentage increase/decrease, and more.
Age Calculator
Calculate your exact age in years, months, and days from your date of birth. Find the age difference between two dates.
BMI Calculator
Calculate your Body Mass Index (BMI) and find out if you are underweight, normal weight, overweight, or obese.
Tip Calculator
Calculate tip amount and total bill. Split the bill between multiple people with custom tip percentages.
Loan Calculator
Calculate monthly payments, total interest, and amortization schedule for any loan amount, rate, and term.
Date Difference Calculator
Calculate the exact number of days, weeks, months, and years between any two dates.
Discount Calculator
Calculate sale prices and savings. Find the final price after single or multiple discounts are applied.
Converters
Unit, measurement, and format converters
Unit Converter
Convert between units of length, weight, temperature, volume, speed, and more. Fast and accurate conversions.
Temperature Converter
Convert between Celsius, Fahrenheit, and Kelvin instantly. See the conversion formula and common temperatures.
Color Converter
Convert colors between HEX, RGB, and HSL formats. Pick colors visually and get all format values instantly.
Inches to CM Converter
Convert inches to centimeters instantly. Includes conversion chart and formula for inches to cm.
CM to Inches Converter
Convert centimeters to inches instantly. Includes cm to inches chart and conversion formula.
Kg to Lbs Converter
Convert kilograms to pounds instantly. Free kg to lbs calculator with conversion table and formula.
Lbs to Kg Converter
Convert pounds to kilograms instantly. Free lbs to kg calculator with conversion table and formula.
Miles to KM Converter
Convert miles to kilometers instantly. Includes miles to km chart, formula, and common distance conversions.
KM to Miles Converter
Convert kilometers to miles instantly. Includes km to miles chart, formula, and common conversions.
Feet to Meters Converter
Convert feet to meters instantly. Free ft to m converter with chart and formula.
Ounces to Grams Converter
Convert ounces to grams instantly. Perfect for cooking, baking, and recipes. Includes oz to g chart.
Cups to ML Converter
Convert cups to milliliters for cooking and baking. US cups, metric cups, and fluid ounces to mL.
Gallons to Liters Converter
Convert gallons to liters and liters to gallons. US and Imperial gallon conversions with chart.
Finance
Mortgage, interest, salary, and business calculators
Compound Interest Calculator
Calculate compound interest on savings and investments. See how your money grows with daily, monthly, or yearly compounding.
Sales Tax Calculator
Calculate sales tax amount and total price. Enter the price and tax rate to find the total cost including tax.
Mortgage Calculator
Calculate monthly mortgage payments, total interest, and see a full amortization schedule. Compare fixed rate loans.
Car Payment Calculator
Calculate monthly car payments based on price, down payment, trade-in value, interest rate, and loan term.
ROI Calculator
Calculate Return on Investment (ROI) to measure the profitability of your investments. Compare multiple investments.
Markup Calculator
Calculate markup percentage, selling price, or cost price. Essential tool for pricing products and services.
Margin Calculator
Calculate profit margin, gross margin, and net margin. Find selling price from cost and desired margin.
Hourly to Salary Calculator
Convert your hourly wage to annual salary. See weekly, biweekly, monthly, and yearly earnings from hourly rate.
Salary to Hourly Calculator
Convert annual salary to hourly wage. Find out what your salary equals per hour, day, week, and month.
Credit Card Payoff Calculator
Calculate how long to pay off credit card debt and total interest. See how extra payments save money.
Health & Fitness
BMI, calories, body fat, and wellness tools
Calorie Calculator
Calculate daily calorie needs based on age, gender, height, weight, and activity level. TDEE and BMR included.
Body Fat Calculator
Estimate body fat percentage using the U.S. Navy method. Enter measurements to calculate body fat and lean mass.
Ideal Weight Calculator
Calculate your ideal body weight based on height and gender using multiple medical formulas (Devine, Robinson, Miller).
Pregnancy Due Date Calculator
Calculate your estimated due date based on last menstrual period or conception date. See trimester timeline.
Water Intake Calculator
Calculate how much water you should drink daily based on weight, activity level, and climate. Stay hydrated.
Pace Calculator
Calculate running or walking pace, speed, distance, or time. Convert between min/mile, min/km, and mph.
Steps to Miles Calculator
Convert steps to miles and kilometers. Find distance walked based on step count and stride length.
Dog Age Calculator
Convert dog years to human years accurately. Uses the latest veterinary science, not the simple 7x rule.
Math
Scientific calculator, fractions, GPA, and statistics
Scientific Calculator
Free online scientific calculator with trigonometry, logarithms, exponents, roots, and advanced math functions.
Fraction Calculator
Add, subtract, multiply, and divide fractions. Simplify fractions and convert between fractions and decimals.
GPA Calculator
Calculate your GPA on a 4.0 scale. Add courses with grades and credit hours to find cumulative GPA.
Square Footage Calculator
Calculate square footage for rooms, homes, and land. Supports rectangular, circular, and triangular areas.
Pythagorean Theorem Calculator
Calculate the missing side of a right triangle using the Pythagorean theorem (a² + b² = c²).
Prime Number Checker
Check if any number is prime. Find prime factors, nearest primes, and generate lists of prime numbers.
Roman Numeral Converter
Convert numbers to Roman numerals and Roman numerals to numbers. Includes reference chart for all values.
Fraction to Decimal Converter
Convert fractions to decimals and decimals to fractions. Shows step-by-step conversion with repeating decimals.
Mean Median Mode Calculator
Calculate mean, median, mode, range, and standard deviation for any data set. Enter numbers to get all statistics.
Developer Tools
JSON formatter, Base64, UUID, and code utilities
JSON Formatter
Format, validate, and beautify JSON data. Minify JSON, fix errors, and view JSON in a tree structure.
Base64 Encode Decode
Encode text to Base64 or decode Base64 to text. Supports UTF-8 encoding and decoding instantly.
URL Encode Decode
Encode or decode URLs and query parameters. Convert special characters to percent-encoded format.
UUID Generator
Generate random UUID/GUID v4 strings. Create single or bulk UUIDs for databases, APIs, and development.
Lorem Ipsum Generator
Generate placeholder text for designs and mockups. Create paragraphs, sentences, or words of lorem ipsum.
Slug Generator
Convert text to URL-friendly slugs. Remove special characters, convert spaces to hyphens, and lowercase.
Hash Generator
Generate MD5, SHA-1, SHA-256, and SHA-512 hashes from text. Compare and verify hash values.
Home & DIY
Paint, concrete, electricity, and fuel calculators
Electricity Cost Calculator
Calculate electricity costs for appliances. Enter watts and hours to find daily, monthly, and yearly energy costs.
Fuel Cost Calculator
Calculate fuel costs for trips and commutes. Enter distance, fuel efficiency, and gas price to estimate costs.
Paint Calculator
Calculate how much paint you need for walls, rooms, and ceilings. Enter dimensions to find gallons needed.
Concrete Calculator
Calculate how many cubic yards or bags of concrete you need for slabs, footings, walls, and columns.
Cooking Converter
Convert cooking measurements between cups, tablespoons, teaspoons, ounces, grams, and milliliters.
Time Zone Converter
Convert times between time zones worldwide. Find the current time in any city or timezone instantly.
Military Time Converter
Convert between military time (24-hour) and standard time (12-hour AM/PM). Includes quick reference chart.
Text Tools
Word counters, case converters, and more
Generators
Passwords, random numbers, and more
Why Use TheQuickCalcs?
Instant Results
Get answers immediately. No loading, no waiting. All calculations happen in your browser.
100% Private
Your data never leaves your device. All tools run entirely in your browser.
Works Everywhere
Desktop, tablet, or phone. Every tool is fully responsive and mobile-friendly.
Over 65 Free Tools at Your Fingertips
TheQuickCalcs offers a comprehensive collection of free online calculators, unit converters, financial tools, health calculators, developer utilities, and text tools. Every tool is designed to be fast, accurate, and easy to use — with no signup, no ads blocking your results, and no data sent to any server.
Whether you need a quick percentage calculation, want to convert units between metric and imperial, plan a mortgage, check your BMI, format JSON, or generate a secure password, we have the right tool for you. All tools work on any device and are completely free to use.