Free tools for everyday calculations. Fast, accurate, and mobile-friendly.
Watt to Volt
Convert watts to volts instantly
Ohm's Law Calculator
Calculate voltage, current, or resistance
BMI Calculator
Calculate your body mass index
Daily Calorie Calculator
Calculate daily calorie needs
Percentage Calculator
Calculate percentages and percentage change
Tip Calculator
Calculate tips for restaurants and services
Loan Calculator
Calculate loan payments and interest
Temperature Converter
Convert between Celsius, Fahrenheit, and Kelvin
Length Converter
Convert between units of length
Weight Converter
Convert between units of weight
Speed Converter
Convert between speed units
Age Calculator
Calculate your exact age
Calcu.tools provides free, accurate, and easy-to-use calculators and unit converters for everyday needs. From electrical engineering tools like our Watt to Volt converter and Ohm's Law calculator, to health tools like BMI and calorie calculators – all optimised for mobile and desktop use. No sign-up required.