Browse All Tools
Every calculator and converter on Smart Utilities Hub, all 43 of them, organized by category. No sign-ups, no ads — just free tools that most run entirely in your browser.
Unit Converters
View category →Length Converter
Instantly convert length units for free — meters, feet, inches, centimeters, kilometers, miles, and yards. No sign-up, accurate results, works on any device.
Mass Converter
Convert mass and weight instantly between kilograms, pounds, ounces, grams, stones, and metric tons — free, accurate to two decimal places.
Temperature Converter
Free temperature converter for Celsius, Fahrenheit, and Kelvin — enter a value and get an instant, precise result with no sign-up, ads, or downloads required.
Volume Converter
Convert volume units instantly and for free — liters, US & UK gallons, cups, milliliters, cubic meters, pints, quarts, and fluid ounces, accurate every time.
Area Converter
Quickly convert area units for free — square meters, square feet, acres, hectares, and square miles, with accurate results and no sign-up needed at all.
Speed Converter
Try our free speed converter for mph, kph, meters per second, knots, and Mach number — instant, accurate conversions that work on any device, no download.
Cooking Volume Converter
Convert cooking measurements for free — cups, tablespoons, teaspoons, milliliters, and fluid ounces — perfect for scaling any recipe up or down accurately.
Timezone Converter
Compare time zones instantly and for free — UTC, EST, PST, GMT, IST, and more, with automatic daylight saving adjustments for accurate cross-region scheduling.
Math Calculators
View category →Basic Calculator
A free online calculator for everyday math — add, subtract, multiply, and divide instantly. Fast, accurate, and works on any device, no sign-up.
Scientific Calculator
Try our free scientific calculator for trigonometry (radians or degrees), logarithms, exponents, and more advanced math — instant, precise results, no sign-up.
Percentage Calculator
Calculate percentages instantly and for free — find what % one number is of another, percentage increase or decrease, all with no sign-up needed at all.
Fraction Calculator
Add, subtract, multiply, and divide fractions for free — convert between fractions, decimals, and mixed numbers, with results simplified automatically.
Square Root Calculator
Calculate the square root, cube root, or any nth root of a number for free with high decimal precision — instant, accurate results, no sign-up needed.
Logarithm Calculator
Free logarithm calculator for natural log, common log, or any custom base — enter a value and get an instant, high-precision result with no sign-up required.
Exponent Calculator
Raise any number to any power for free — compute roots via fractional exponents, with results shown in scientific notation automatically when needed.
Slope Calculator
Calculate the slope between two points for free — enter two coordinates to find rise over run instantly, with no sign-up needed.
Pythagorean Theorem
Solve right triangles for free using the Pythagorean theorem — find the hypotenuse or a missing leg instantly, accurate to any level of precision, no sign-up.
Graphing Calculator
Plot multiple functions overlaid for free with our interactive graphing calculator — each in its own color with a legend, instant results in your browser.
Financial Calculators
View category →Currency Converter
Convert between 161 world currencies instantly using live exchange rates — free, accurate, and refreshed automatically every time you load the tool.
Compound Interest Calculator
Calculate compound interest growth for free with custom compounding frequencies — see year-by-year breakdowns and future value projections, no sign-up.
Mortgage Calculator
Estimate mortgage payments for free with a full amortization schedule — see principal versus interest breakdowns over your entire loan term, instantly.
Investment Growth Calculator
Project investment growth for free with regular contributions — see how your money compounds over time with clear, year-by-year value estimates, no sign-up.
Retirement Calculator
Plan your retirement for free with projections for savings growth, withdrawal rates, and income — includes an optional Social Security estimate, no sign-up.
Tax Calculator
Estimate your income tax for free using progressive tax brackets — enter your income and filing status for an instant, easy-to-read tax estimate, no sign-up.
Salary Converter
Convert salary between hourly, daily, weekly, monthly, and annual pay for free — factor in your work hours for an instant gross-pay breakdown, no sign-up.
Profit Calculator
Calculate gross profit and profit margin for free from your revenue and cost of goods sold — instant, accurate results for pricing any product or service.
Sales Tax Calculator
Calculate sales tax and total price for free — just enter the original amount and tax rate for an instant, accurate breakdown of what you'll owe, no sign-up.
Tip Calculator
Split the bill and calculate tips for free — enter your total and party size for an instant per-person breakdown, accurate down to the cent every time.
Discount Calculator
Work out discounts and sale prices for free — enter the original price and percentage off to get an instant, accurate final price with no sign-up needed.
Markup Calculator
Find markup percentage, selling price, or cost for free — enter any two values to instantly solve for the third, ideal for retail and e-commerce pricing.
Health Calculators
View category →BMI Calculator
Instantly calculate your BMI for free in metric or imperial units — enter your weight and height to get your Body Mass Index and weight category.
Calorie Needs Calculator
Estimate your daily calorie needs for free using the Mifflin-St Jeor equation — enter your age, weight, height, and activity level for an instant result.
Date & Time Tools
View category →Age Calculator
Calculate your exact age for free in years, months, and days — enter your birthdate and optionally a comparison date for an instant, precise result, no sign-up.
Date Difference Calculator
Find the number of days between any two dates for free — perfect for countdowns, deadlines, and scheduling, with instant, accurate results every time.
Add Days to Date Calculator
Add or subtract days from any date for free — enter a start date and a number of days for an instant result that correctly handles month and year boundaries.
Developer Tools
View category →Text Tools
View category →Case Converter
Convert text between UPPER CASE, lower case, and Title Case for free — paste your text and get an instant result with no sign-up, ads, or downloads required.
Character Counter
Count characters in your text for free, with and without spaces — instant, accurate results for writers, students, and anyone tracking text length, no sign-up.
Word Counter
Count words in any text instantly and for free — perfect for essays, articles, and content writing, with no limit on text length and no sign-up needed.
Text Compressor
Compress and decompress text for free using LZ-String or Pako gzip — reduce text size for storage or transmission, entirely inside your browser, no upload.
Creative Tools
View category →QR Code Generator
Generate custom QR codes for free — embed URLs, text, or contact info, customize colors and sizes, and download instantly with no sign-up or watermark added.
Color Converter
Free color converter for HEX, RGB, HSL, and HSV formats — pick a color and see a live preview update instantly as you type, with no sign-up required at all.
Image Processor
Resize, crop, and edit images for free right in your browser — adjust brightness and apply filters instantly, with nothing ever uploaded to a server at all.