78+ Free Online Tools:
Calculators, Generators & Converters
No registration, no downloads. Use them directly from your browser. All tools run on your device — your data never leaves your computer.
Health & Wellness
See allHealth
BMI Calculator
Calculate your Body Mass Index and see your WHO weight classification.
Health
Daily Calorie Calculator
Calculate how many calories you need per day based on your activity level.
Health
Ideal Weight Calculator
Find your ideal weight range based on your height, age, and gender.
Health
Body Fat Percentage Calculator
Estimate your body fat percentage using basic body measurements.
Health
Pregnancy Due Date Calculator
Calculate your estimated due date and current week of pregnancy.
Health
Menstrual Cycle Calculator
Predict your next periods and fertile window based on your cycle.
Health
Heart Rate Zones Calculator
Calculate your maximum heart rate and optimal training zones.
Health
Daily Water Intake Calculator
Calculate how much water you should drink each day.
Health
Intermittent Fasting Timer
Track your fasting windows with 16:8, 18:6, 20:4, and OMAD protocols.
Math & Education
See allMath
Percentage Calculator
Calculate percentages, increases, discounts, and proportions.
Math
Rule of Three Calculator
Solve direct and inverse rule of three (cross-multiplication) problems.
Math
Average/Mean Calculator
Calculate the mean, median, and mode of a set of numbers.
Math
Final Grade Calculator
Calculate your weighted final grade and the minimum score needed to pass.
Math
Fraction Calculator
Add, subtract, multiply, and divide fractions step by step.
Math
Unit Converter
Convert between units of length, weight, volume, and temperature.
Math
Area & Perimeter Calculator
Calculate the area and perimeter of common geometric shapes.
Math
GCD & LCM Calculator
Calculate the Greatest Common Divisor and Least Common Multiple.
Math
Roman Numeral Converter
Convert between Arabic numbers and Roman numerals.
Math
Equation Solver
Solve linear and quadratic equations with step-by-step solutions.
Math
Square Root Calculator
Calculate square roots, cube roots, and nth roots of any number.
Math
Exponent/Power Calculator
Calculate powers and exponents of any number.
Math
Logarithm Calculator
Calculate logarithms in base 10, natural log (ln), and any custom base.
Math
Multiplication Table Generator
Generate multiplication tables from 1 to 100 for studying.
Math
Standard Deviation Calculator
Calculate standard deviation, variance, and other statistics for a data set.
Math
Combinations & Permutations Calculator
Calculate combinations (nCr) and permutations (nPr) with factorials.
Math
Scientific Notation Converter
Convert numbers to and from scientific notation (E notation).
Math
Matrix Calculator
Perform matrix operations: addition, multiplication, determinant, and inverse.
Time & Dates
See allTime
Age Calculator
Calculate your exact age in years, months, and days from your birth date.
Time
Day Counter / Date Difference
Calculate the number of days between two dates including business days.
Time
Work Hours Calculator
Calculate total hours worked and estimated pay from clock-in times.
Time
Countdown Timer
Set a countdown timer with alarm sound for any duration.
Time
Date Calculator
Add or subtract days, weeks, or months from any date.
Time
Online Stopwatch
Stopwatch with lap recording and millisecond precision.
Time
World Clock
Check the current time in cities around the world and compare time zones.
Time
Business Days Calculator
Calculate business days between dates excluding weekends and US holidays.
Time
US Holiday Calendar
View all US federal holidays and observances by year.
Finance & Business
See allFinance
Sales Tax Calculator
Calculate sales tax for any US state and find the total price.
Finance
Federal Income Tax Calculator
Estimate your US federal income tax based on current tax brackets.
Finance
Loan/Amortization Calculator
Calculate monthly payments, total interest, and view an amortization schedule.
Finance
Compound Interest Calculator
Calculate the growth of your investment with compound interest over time.
Finance
Tip Calculator
Calculate the tip amount and split the bill between multiple people.
Finance
Savings Goal Calculator
Plan how much to save monthly to reach your financial goal.
Finance
Paycheck Calculator
Estimate your take-home pay after federal and state tax deductions.
Finance
Hourly to Salary Converter
Convert between hourly wages and annual salary equivalents.
Finance
401k/Retirement Calculator
Estimate your retirement savings and 401(k) growth over time.
Finance
Mortgage Calculator
Calculate your monthly mortgage payment with taxes and insurance.
Finance
Inflation Calculator
Calculate how inflation affects the purchasing power of your money.
Finance
ROI / Investment Return Calculator
Calculate your return on investment (ROI) and annualized returns.
Code & Generators
See allCode
QR Code Generator
Create custom QR codes and download them as PNG or SVG.
Code
Barcode Generator
Create barcodes in EAN-13, UPC-A, Code 128, and more formats.
Code
UUID Generator
Generate universally unique identifiers (UUID v4) instantly.
Code
Number Base Converter
Convert between binary, octal, decimal, and hexadecimal.
Code
Color Picker & Converter
Pick colors and convert between HEX, RGB, and HSL formats.
Code
WiFi QR Code Generator
Create a QR code to share your WiFi network instantly.
Code
vCard QR Generator
Create a QR code with your digital contact card information.
Productivity & Utilities
See allProductivity
Password Generator
Generate strong, random passwords with customizable options.
Productivity
Lorem Ipsum Generator
Generate placeholder text by paragraphs, sentences, or words.
Productivity
Word Counter
Count words, characters, sentences, and reading time of any text.
Productivity
Character Counter
Count characters with social media limit indicators for Twitter, Instagram, and more.
Productivity
Case Converter
Convert text to UPPERCASE, lowercase, Title Case, and more.
Productivity
Random Name Generator
Generate random names for people, businesses, or projects.
Productivity
Word Frequency Counter
Analyze the frequency of each word in a text.
Productivity
Text Cleaner
Remove extra spaces, line breaks, special characters, and formatting.
Productivity
JSON to CSV / CSV to JSON
Convert data between JSON and CSV formats instantly.
Productivity
Email Signature Generator
Create professional HTML email signatures for Gmail, Outlook, and more.
Productivity
Line Counter
Count lines of text or code including blank lines and comments.
Productivity
Markdown/HTML Table Generator
Generate tables in HTML, Markdown, and plain text formats.
Productivity
Text Compare / Diff Tool
Compare two texts side by side and highlight the differences.
Productivity
Base64 Encoder/Decoder
Encode and decode text in Base64 format.
Productivity
URL Encoder/Decoder
Encode and decode URLs and query string parameters.
Productivity
HTML/CSS/JS Minifier
Minify and beautify HTML, CSS, and JavaScript code.
Productivity
Syllable Counter
Count the syllables in any word or text in English.
Productivity
Hash Generator
Generate MD5, SHA-1, SHA-256, and other cryptographic hashes.
Productivity
Regex Tester
Test and debug regular expressions with real-time matching.
Productivity
JSON Formatter / Beautifier
Format, validate, and beautify JSON data with syntax highlighting.
Productivity
Pomodoro Timer
Boost productivity with the Pomodoro Technique work/break timer.
Conversion
See allFree online tools for everyday tasks
toolsusa.online is a free online tools platform built for the United States and English-speaking users worldwide. We bring together over 78 calculators, generators, converters, and utilities you can use directly from your browser — no registration or downloads required.
Our financial calculators — including the income tax calculator, paycheck calculator, sales tax calculator, mortgage calculator, and 401(k) planner — use current IRS brackets, federal rates, and US-specific data. If you need to calculate percentages, solve proportions, or find an average, our math calculators give you instant results with step-by-step explanations.
All tools process your data locally in your browser. Nothing is sent to an external server — your information stays on your device. From generating QR codes and secure passwords to converting images and counting words, every tool is designed to be fast, simple, and work on any device — phone, tablet, or desktop.
Frequently Asked Questions
- Are the tools really free?
- Yes, all 80+ tools on toolsusa.online are completely free. You don't need to create an account, subscribe, or provide any payment information to use them.
- Do I need to create an account?
- No, all tools work without registration. No account, login, or sign-up is required. Simply open the tool you need and use it directly from your browser.
- Is my data safe?
- Yes, all calculations happen in your browser. Your data is never sent to any server — all processing, conversions, and computations are performed locally on your device.
- Can I use them on mobile?
- Yes, all tools are fully responsive and optimized for mobile devices. They work on any modern browser, whether on your phone, tablet, or desktop computer.
- Do financial tools use US data?
- Yes, tax calculators use IRS 2025 brackets and rates. Financial tools like the income tax calculator, paycheck calculator, and sales tax calculator are built with up-to-date US federal and state data.
- Do I need to download anything?
- No, everything runs in your browser. You don't need to download or install any software, plugins, or applications. All tools work instantly online.