Science, Units & Digital Calculators
Conversions, chemistry, weather and web.
Convert units of every kind, compute density, molarity and half-life, estimate wind chill and dew point, and handle digital tasks like Base64, subnets and DPI.
All 26 science, units & digital calculators
Aspect Ratio CalculatorFind a width or height that keeps a target aspect ratio. Useful for resizing images and video to 16:9, 4:3, 1:1 or any custom ratio.Bandwidth CalculatorEstimate how long a file takes to transfer at a given connection speed, and see why advertised megabits do not translate into megabytes per second.Base64 Encode / Decode CalculatorEncode text to Base64 or decode Base64 back to plain text. Works in both directions for data URIs, API payloads and basic-auth headers.Carbon Footprint CalculatorEstimate monthly CO2 emissions from your energy use and travel, so you can see which part of your household footprint actually dominates.Conversion CalculatorConvert a value between units within length, mass, volume, area, speed, data, energy or pressure.Cooking Measurement ConverterConvert recipe amounts between cups, tablespoons, teaspoons, millilitres, grams and ounces, switching between volume and weight measures.Data Storage ConverterConvert digital storage between bits, bytes, KB, MB, GB, TB and more, so you can compare file sizes and drive capacities on the same scale.Density CalculatorSolve for density, mass or volume using ρ = m / V. Pick which quantity you need and enter the other two in kilograms and cubic meters.Dew Point CalculatorCalculate the dew point from air temperature and relative humidity — a better guide to how muggy the air feels than humidity alone.Half-Life CalculatorFind how much of a substance remains after a given time using its half-life.Heat Index CalculatorCalculate the "feels like" heat index from temperature and relative humidity.Ideal Gas Law CalculatorSolve PV = nRT for pressure, volume, moles or temperature. Enter any three values in atmospheres, liters, moles and kelvin to find the fourth.IP Subnet CalculatorFind the network address, broadcast address, usable host range and subnet mask for any IPv4 address and CIDR prefix.Length ConverterConvert a length between metric and imperial units — millimeters, centimeters, meters and kilometers to inches, feet, yards and miles.Mass CalculatorCalculate mass from density × volume, or from force ÷ acceleration using Newton’s second law. Pick whichever mode fits the data you have.Molarity CalculatorSolve for molarity, moles or volume using M = moles / liters. Choose which quantity to find and enter the other two to get the concentration.Molecular Weight CalculatorFind the molar mass of a compound from its chemical formula, summing the atomic weights of every element in grams per mole.Password GeneratorGenerate a random password from chosen character sets — uppercase, lowercase, numbers and symbols — with an entropy-based strength rating.pH CalculatorCalculate pH from hydrogen-ion concentration, or the concentration from a pH.Pixel / DPI CalculatorRelate pixels, DPI and print size, and solve for any one of the three. Check whether an image has enough resolution to print at a given size.Projectile Motion CalculatorFind the range, maximum height and flight time of a projectile from its launch speed and angle, ignoring air resistance.Speed CalculatorCalculate average speed from a distance and a time. The result is shown in meters per second, kilometers per hour and miles per hour.Temperature ConverterConvert temperatures between Celsius, Fahrenheit and Kelvin. Enter any one value and get the other two scales instantly.URL Encode / Decode CalculatorPercent-encode text for URLs or decode an encoded string. Handles spaces, query parameters and special characters safely in both directions.Weight CalculatorCalculate weight (force) from mass and gravity using W = m·g. Results in newtons and pounds-force, with adjustable gravity for other planets.Wind Chill CalculatorCalculate the National Weather Service wind chill from temperature and wind speed.