Unit Converters

Unit and currency converters

Length. Whether you are buying fabric, planning a road trip or ordering timber, converting between length units is one of the most common everyday needs. Our length converter handles metres, centimetres, millimetres, kilometres, inches (1 inch = 2.54 cm), feet (1 foot = 30.48 cm), yards and miles (1 mile = 1.609 km). Knowing these relationships helps when reading product specifications from international shops or interpreting measurements from British and American sources.

Weight and mass. Recipes, medical records and product labels routinely mix metric and imperial weight units. The weight converter covers kilograms, grams, milligrams, tonnes, pounds (1 lb = 0.4536 kg), ounces (1 oz = 28.35 g) and stones. A stone equals 14 pounds, and is still widely used for body weight in the UK — so the converter is especially useful for anyone following British dietary or fitness guidelines.

Temperature. Three temperature scales appear in daily life: Celsius (used across most of the world), Fahrenheit (standard in the USA) and Kelvin (the SI base unit used in science). The conversions are: °C = (°F − 32) × 5/9 and K = °C + 273.15. Practical reference points: water boils at 100 °C / 212 °F, body temperature is 37 °C / 98.6 °F, a typical oven temperature of 350 °F equals 177 °C, and absolute zero is 0 K = −273.15 °C.

Area. Real estate listings, garden plans and agricultural land are measured in square metres, square kilometres, hectares (1 ha = 10 000 m²), acres (1 acre = 4 046.86 m²) and square feet. The area converter lets you compare land sizes across national conventions — useful when evaluating a property for sale abroad.

Volume. Cooking, fuel and chemistry all involve volume units that vary by country. The converter includes litres, millilitres, cubic metres, US gallons (1 US gal = 3.785 L), UK gallons (1 UK gal = 4.546 L), cups (1 cup = 240 ml) and tablespoons (1 tbsp = 15 ml). The difference between US and UK gallons matters when filling a tank or scaling a recipe from an American source.

Speed. Speed converters are essential for sport, driving and aviation: 1 m/s = 3.6 km/h; 1 mph = 1.609 km/h; 1 knot = 1.852 km/h. Athletes tracking pace, pilots reading airspeed and drivers checking speed limits all benefit from quick conversion.

Digital data. Cloud storage plans, file sizes and internet speeds use binary prefixes: 1 KB = 1 024 B, 1 MB = 1 024 KB, 1 GB = 1 024 MB, 1 TB = 1 024 GB. The data size converter also handles bits versus bytes, which is critical when reading broadband speeds (quoted in megabits per second, not megabytes).

Currency. Exchange rates between PLN, EUR, USD and GBP change daily. Our currency converter fetches live mid-market rates from NBP — the National Bank of Poland — so you always see an up-to-date reference rate. Note that banks and exchange offices apply a spread, so the rate you actually receive will differ slightly.

Clothing and shoe sizes. EU, US and UK sizing systems follow different scales for clothing, shoes and bras. The size converter maps standard EU sizes to their US and UK equivalents so you can shop confidently from international online stores.

For the underlying mathematical formulas behind unit conversions, see the matematyka category. All converters on Liczbnik work instantly in the browser, are free, and require no registration.