Fast, accurate, and easy-to-use tools for everyday calculations and conversions. All tools are free and work directly in your browser.
Advanced calculator with scientific functions
Basic arithmetic calculator for quick calculations
Large display calculator for easy viewing
Virtual abacus for learning and practice
Calculate percentages, increases, and decreases
Calculate your Body Mass Index
Calculate materials for your patio project
Track and calculate dart scores
Comprehensive math problem solver
Convert between meters, feet, inches, and more
Convert between kilograms, pounds, ounces
Convert liters, gallons, cups, and more
Convert Celsius, Fahrenheit, and Kelvin
Convert km/h, mph, m/s, and more
Convert hours, minutes, seconds, days
Convert between US, UK, and EU ring sizes
Online Calculator Kit provides free, professional-grade calculators and unit converters for everyday use. All tools work directly in your browser with instant results, no installation required.
Yes! All our calculators and converters are 100% free to use. No registration, no hidden fees, no subscriptions.
No downloads required. All tools work directly in your web browser. Just visit, use, and get instant results.
Absolutely! All calculations are processed locally in your browser. We never see, store, or transmit your data.
Yes! All our tools are fully responsive and work perfectly on phones, tablets, and desktop computers.
Once you've loaded a page, most calculators will continue working even if you lose internet connection.