Free Online Calculators
Welcome to Simple Calculator — your free platform for online calculators and unit converters, no sign-up required. With over 55 calculators in 10 languages, you'll find the right tool for every task: fast, accurate and running entirely in your browser — no app, no account, no data shared.
The foundation is 16 unit converters covering all key physical quantities: pressure (bar, PSI, Pascal, atm), length (km, miles, feet, inches), weight (kg, pounds, ounces, tons), temperature (Celsius, Fahrenheit, Kelvin), area, volume, speed, energy, power, force, torque, data size, time, angle, density and fuel consumption. Every converter shows the underlying formula and a table of the most common unit pairs.
The Building & Home category covers 7 calculators: concrete calculator (cement, sand, gravel and water for any concrete grade), wallpaper calculator (including pattern repeat waste), screed calculator (material and drying time), pool chemistry calculator, solar PV calculator, utility cost calculator and circuit breaker calculator. Energy & Electrical adds 3 more: LED savings, energy consumption per device and cable cross-section. The Garden section offers 4 tools for soil, lawn fertiliser, plant spacing and rainwater tank sizing.
Three health calculators: calorie deficit, daily water intake and sleep cycle calculator. Four kitchen tools: recipe scaler, baking pan converter, jam calculator and dough proofing calculator. Crafters will find fabric, yarn and bead calculators. Pet owners get the aquarium calculator and the pet food calculator for dogs and cats. The office section covers DPI, paper weight and printing cost. Transport tools include discount, moving box and towing capacity calculators. The 10 everyday and financial calculators span BMI, mortgage, compound interest, percentage, VAT, fuel cost, tip, age, pace and calorie calculators. Everything free, no registration, in 10 languages: German, English, French, Spanish, Italian, Turkish, Portuguese, Dutch, Polish and Japanese.