Categories
Table of contents

Conversion calculator

Views25

Use this conversion calculator to convert between commonly used units.

Select the current unit in the left column, the desired unit in the right column, and enter a value in the left column to generate the resulting conversion.

From:

To:

Related calculators:

Day of the weekLeap yearTemperature conversion

The evolution of measurement systems

The US Customary System traces its origins back to the British Imperial system, with slight modifications when the United States gained independence. Although the US adopted many of the same units for weight, length, and volume as the British, certain measurements, such as the gallon, were adjusted, making the US gallon smaller than the Imperial gallon. This system has remained largely unchanged in the United States, despite the global shift toward the Metric System for most scientific, commercial, and everyday use.

In contrast, the Metric System was developed in France during the late 18th century as part of the French Revolution’s broader effort to standardize measurements across the country. Revolutionary leaders sought a logical, uniform, and decimal-based system to replace the confusing and varied local measurements in use at the time. The meter, for example, was defined as 1/10,000,000 of the distance from the North Pole to the Equator along the meridian through Paris. The Metric System’s emphasis on powers of ten made conversions simpler, and as the 19th century progressed, the system spread globally, eventually evolving into the International System of Units (SI) in 1960, becoming the global standard.

By the mid-20th century, most countries had adopted the Metric System for both scientific and everyday use, largely due to the need for international standardization in trade and science. However, the Imperial and US systems continued to be used in the United States and some parts of the United Kingdom, particularly in everyday life and specific industries, such as construction and aviation. While the Metric System became the preferred standard worldwide, the persistence of these traditional systems in certain countries demonstrates the continued cultural influence of older units.

Today, the SI System, a modernized version of the Metric System, serves as the universal standard for most global scientific, industrial, and commercial measurements. Despite the widespread adoption of the Metric System, the Imperial and US Customary systems remain entrenched in the United States, reflecting a unique blend of historical legacy and cultural preference in how measurements are understood and used.

Different systems of units

Here’s an overview of some of the most commonly used systems:

1. Metric system (SI – International System of Units)

  • Length: Meter (m)
  • Mass/weight: Kilogram (kg)
  • Temperature: Celsius (°C)
  • Area: Square meter (m²)
  • Volume: Cubic meter (m³)
  • Speed: Meters per second (m/s)
  • The Metric System is the most widely used system of measurement across the world, especially in scientific, academic, and most everyday applications. It is based on powers of 10, making conversions straightforward.

2. Imperial system (UK) / British Imperial

  • Length: Inch (in), Foot (ft), Yard (yd), Mile (mi)
  • Mass/Weight: Pound (lb), Ounce (oz), Stone (st)
  • Temperature: Fahrenheit (°F)
  • Area: Square foot (ft²), Square yard (yd²), Acre
  • Volume: Pint (pt), Quart (qt), Gallon (gal), Cubic foot (ft³)
  • Speed: Miles per hour (mph)
  • The Imperial system is primarily used in the United States and to some extent in the United Kingdom (for certain purposes).

3. US customary system (USCS)

  • Similar to the Imperial system, the US Customary System is used in the United States for everyday measurements.
  • Length: Inch (in), Foot (ft), Yard (yd), Mile (mi)
  • Mass/Weight: Pound (lb), Ounce (oz), Ton (short ton)
  • Temperature: Fahrenheit (°F)
  • Area: Square foot (ft²), Acre
  • Volume: Fluid ounce (fl oz), Pint (pt), Quart (qt), Gallon (gal)
  • Speed: Miles per hour (mph)
  • The main difference between USCS and the British Imperial system is the size of certain units, such as the US gallon and pint.

4. Chinese system

  • Length: Chi (尺), Cun (寸)
  • Mass/Weight: Jin (斤), Liang (两)
  • Temperature: Celsius (°C) or traditional Chinese units in some contexts.
  • Area: Mu (亩)
  • Volume: Liter (L) or traditional Chinese units in some contexts.
  • Speed: Meters per second (m/s), or kilometers per hour (km/h) for modern usage.
  • The traditional Chinese system is still used in certain cultural contexts but has largely been replaced by the metric system.

5. Japanese system

  • Length: Shaku (尺), Sun (寸)
  • Mass/Weight: Kan (貫), Momme (匁)
  • Temperature: Celsius (°C)
  • Area: Tsubo (坪)
  • Volume: Liter (L) or traditional Japanese units in some contexts.
  • Speed: Kilometers per hour (km/h) or meters per second (m/s) for modern usage.
  • Like China, Japan has adopted the metric system for most modern measurements.

6. Ancient units

  • Length: Cubit (used in ancient Egypt), Fathom (used for measuring depth, commonly used in nautical contexts).
  • Mass/weight: Talent, Shekel (used in ancient Mesopotamia and Hebrew cultures).
  • Area/volume: Homer (ancient Greek unit for liquid measure), Stater (coin used for weight measure).
  • Speed: Not a commonly standardized unit, but terms like “leap” or “pace” might be used in historical contexts.
  • These units were used in various ancient civilizations and have mostly been replaced by modern systems.

Key conversion factors between systems

Here are a few conversion factors between some of the most common systems:

  • Length:
    • 1 meter = 39.37 inches (Imperial), 3.2808 feet (US Customary)
    • 1 inch = 2.54 cm
    • 1 mile = 1.60934 kilometers
  • Weight:
    • 1 kilogram = 2.20462 pounds (Imperial/US)
    • 1 pound = 16 ounces
  • Temperature:
    • °F = (°C × 9/5) + 32
    • °C = (°F – 32) × 5/9
  • Speed:
    • 1 meter per second = 3.6 kilometers per hour
    • 1 mile per hour = 1.60934 kilometers per hour

Some other key systems

  • Astronomical Units: Used to measure vast distances in space (e.g., light years, parsecs).
  • Nautical Units: Used in maritime contexts, such as knots for speed, fathoms for depth.

These units are often used depending on the context, with the metric system being dominant in scientific, international, and most of the modern world, while imperial or US customary systems are still in use in the United States, parts of the UK, and some other regions.