Free Online Calculators & Tools
Over 75 powerful calculators and utilities for health, finance, text, design, and more - all free and easy to use
Health & Fitness Calculators
BMI Calculator
Calculate your Body Mass Index and check if you're at a healthy weight
Calorie Calculator
Find out how many calories you need per day to maintain, lose, or gain weight
Body Fat Calculator
Estimate your body fat percentage using the US Navy method
BMR Calculator
Calculate your Basal Metabolic Rate - calories burned at rest
Ideal Weight Calculator
Find your ideal body weight based on scientific formulas
Healthy Weight Calculator
Calculate your healthy weight range based on BMI
Lean Body Mass Calculator
Calculate your lean body mass and body composition
Body Type Calculator
Determine your body shape type based on measurements
Pace Calculator
Calculate running and walking pace for training
Bra Size Calculator
Calculate accurate bra size and find sister sizes
Pregnancy Calculator
Calculate your due date and track pregnancy milestones
Conception Calculator
Calculate estimated conception date from due date
Due Date Calculator
Calculate pregnancy due date from last menstrual period
Period Calculator
Track menstrual cycle and predict future periods
Sleep Cycle Calculator
Calculate optimal bedtime and wake time for better sleep
Finance Calculators
Loan Calculator
Calculate monthly payments, total interest, and amortization schedules
Investment Calculator
Calculate investment growth with regular contributions over time
Compound Interest Calculator
See how your money grows with compound interest over time
ROI Calculator
Calculate Return on Investment for your business decisions
Inflation Calculator
Calculate the impact of inflation on purchasing power
Income Tax Calculator
Calculate federal income tax based on 2024 brackets
Stripe Fee Calculator
Calculate Stripe payment processing fees and net payout
Fuel Cost Calculator
Calculate fuel costs for trips and compare vehicles
Text Tools
Word Counter
Count words, characters, sentences, and paragraphs in your text
Case Converter
Convert text to uppercase, lowercase, title case, and more
Text Replace
Find and replace text with advanced options
Reverse Text
Reverse your text, words, or letters instantly
Remove Duplicate Lines
Remove duplicate lines from your text quickly
Remove Empty Lines
Clean up text by removing empty lines
Remove Spaces
Remove extra spaces and clean up formatting
Convert Tabs to Spaces
Convert tabs to spaces for code standardization
Tiny Text Generator
Convert text to tiny Unicode characters
HTML Text Generator
Convert special characters to HTML entities
Text Summarizer
Summarize long text into key points
Time & Date Tools
Date Calculator
Add or subtract days, months, and years from any date
Time Calculator
Add, subtract, and calculate time durations easily
Date Duration Calculator
Calculate the duration between two dates
Time Converter
Convert between different time units
Online Stopwatch
Accurate stopwatch with lap timer functionality
Online Timer
Set a countdown timer for any duration
Lap Timer
Professional lap timer with split times
Chess Timer
Two-player chess clock for tracking game time
Classroom Timer
Large display timer for exams and presentations
Design Tools
Aspect Ratio Calculator
Calculate and resize images while maintaining aspect ratio
16:9 Aspect Ratio
Calculate dimensions for widescreen 16:9 format
4:3 Aspect Ratio
Calculate dimensions for standard 4:3 format
Social Media Ratios
Optimal image dimensions for social platforms
Hex Color Generator
Generate random hex color codes for your designs
Color Theme Generator
Generate complete color themes from a base color
RGB to HEX Converter
Convert RGB color values to hexadecimal codes
Math & Number Tools
Basic Calculator
Simple arithmetic calculator for everyday calculations
Scientific Calculator
Advanced calculator with trigonometric and logarithmic functions
Binary Calculator
Perform calculations with binary numbers
Number Converter
Convert between decimal, binary, hexadecimal, and octal
Random Number Generator
Generate random numbers within a custom range
Temperature Converter
Convert between Celsius, Fahrenheit, and Kelvin
Statistics Tools
Probability Calculator
Calculate simple and compound probabilities
Sample Size Calculator
Calculate required sample size for surveys and research
Standard Deviation Calculator
Calculate standard deviation and variance of datasets
Seasonal Index Calculator
Calculate seasonal indices for time series data
Utility & Generator Tools
Random Name Picker
Randomly select names from a list
Random Group Generator
Create random groups from a list of names
List Randomizer
Randomly shuffle and reorder lists
Lottery Number Picker
Generate random lottery numbers
Lotto Number Generator
Generate lotto numbers for various games
Lucky Number Generator
Generate your lucky numbers
Keno Number Generator
Generate random keno numbers for games
Network Tools
Holiday Countdowns
Why Use SWTools?
SWTools provides a comprehensive collection of free online calculators and tools designed to make your everyday tasks easier. Whether you're calculating your BMI, planning a loan, counting words in a document, or converting colors for a design project, we have the tools you need.
Accurate and Easy to Use
All our calculators are built with accuracy in mind, using industry-standard formulas and methods. The interface is clean and intuitive, making it easy for anyone to use our tools without confusion. Simply enter your values, and get instant results.
No Registration Required
We believe in keeping things simple. You don't need to create an account or provide any personal information to use our tools. Everything is completely free and accessible right from your browser.
Mobile-Friendly Design
All our calculators work perfectly on desktop computers, tablets, and smartphones. The responsive design ensures that you can access our tools from any device, anywhere, anytime.
Privacy Focused
Your calculations are processed in your browser and are never stored on our servers. We respect your privacy and don't track or save any of the data you enter into our calculators.
Popular Calculator Categories
Health & Fitness Calculators
Our health calculators help you track your fitness journey. Calculate your BMI to check if you're at a healthy weight, determine your daily calorie needs for weight management, find your ideal weight based on scientific formulas, and track pregnancy milestones. These tools are designed to give you insights into your health metrics, but remember to always consult with healthcare professionals for medical advice.
Financial Calculators
Make informed financial decisions with our finance calculators. Whether you're taking out a loan, planning an investment, or calculating returns, our tools provide detailed breakdowns and projections. The loan calculator shows you monthly payments and total interest, while the investment calculator helps you plan for the future by showing how your money can grow over time with compound interest.
Text Manipulation Tools
Writers, students, and content creators love our text tools. The word counter is perfect for meeting essay requirements or staying within social media limits. Case converters help you format text consistently, and our text cleaning tools can remove duplicates, empty lines, and extra spaces with a single click.
Time & Date Calculators
Calculate time differences, add or subtract dates, and track durations with our time and date tools. These are particularly useful for project planning, event countdown, age calculations, and understanding time zone differences. Our timers and stopwatches are perfect for fitness, cooking, studying, and classroom use.
Design Tools
Designers and content creators appreciate our aspect ratio calculators and color tools. Maintain perfect proportions for images and videos, generate color palettes, and convert between different color formats. These tools streamline your creative workflow and ensure consistent, professional results.