Conversions calculators

Convert acres, hectares, square feet, square meters, square yards, square miles and km² in one step, with exact factors and a land-size reference table.

Convert cups, tablespoons, teaspoons, mL and fl oz to grams and ounces for flour, sugar, butter, honey and more — using King Arthur Baking's ingredient weights.

Convert between 31 currencies at the European Central Bank's daily reference rates, with the exact rate, the inverse, and every currency listed at once.

Convert bits, bytes, KB, MB, GB and TB — and the binary KiB, MiB, GiB, TiB — and see why a 1 TB drive shows up as 931 GB. Decimal vs binary explained.

Convert between inches, feet, yards, miles, millimeters, centimeters, meters, kilometers and nautical miles — all at once, with exact factors and a reference table.

Convert 12-hour AM/PM times to 24-hour military time and back, hear how to say it ('fourteen thirty hours'), and use the full 24-hour reference chart.

Convert any number from 1 to 3,999 into Roman numerals with each place value shown, plus charts of 1–100, hundreds, thousands and famous years like MCMXCIV.

Convert a measured foot length to US, UK, EU and Japanese shoe sizes for men, women and children, using the Brannock Device's own published scales.

Convert mph, km/h, m/s, ft/s and knots instantly, and see the equivalent running pace in minutes per mile and per kilometer, with speed-limit and wind tables.

Convert Celsius, Fahrenheit and Kelvin exactly, with the formula worked step by step, a weather and cooking reference table and the quick mental shortcuts.

Convert liters, milliliters, US cups, tablespoons, teaspoons, fluid ounces, pints, quarts, gallons and cubic feet at once — with the kitchen and US-vs-UK tables.

Convert pounds, ounces, stone, kilograms, grams, milligrams and tons in one go using the exact 1959 definitions — with a body-weight table and cooking equivalents.