Smart Utilities Hub
A collection of 43 free online calculators and converters — built to be fast, private, and always free. No sign-ups.
Popular Tools
The most-used calculators and converters on Smart Utilities Hub.
BMI Calculator
Instantly calculate your BMI for free — enter height and weight in metric or imperial units to get your Body Mass Index, category, and healthy weight range.
Mortgage Calculator
Estimate mortgage payments for free with a full amortization schedule — see principal versus interest breakdowns over your entire loan term, instantly.
Currency Converter
Convert 10 major currencies instantly using live exchange rates — USD, EUR, GBP, JPY, AUD, CAD, CHF, CNY, INR, and ZAR, refreshed automatically, free to use.
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.
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.
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.
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.
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.
Explore by Category
All 42 tools organized into 8 categories. Find exactly what you need.
Unit Converters
Length, mass, temperature, volume, area, speed, cooking, and timezone
Math Calculators
Scientific, percentage, fractions, square root, logs, exponents, slope, and graphing
Financial Calculators
Currency, mortgage, compound interest, retirement, tax, profit, tips, and discounts
Health Calculators
BMI calculator and daily calorie needs — evidence-based, metric or imperial
Date & Time Tools
Age calculator, date difference, and add/subtract days from any date
Developer Tools
Code formatter for JavaScript, HTML, CSS, and JSON — client-side, no uploads
Text Tools
Case converter, word counter, character counter, and text compressor
Creative Tools
QR code generator, color converter, and image processor