Galaxynet :: Metric Conversion

This page provides automatic conversion of some units of measurement to be found in use around the world today (and a few of historical interest), so you can change them into a 'standard' unit of the SI. Le Systeme international d'Unites officially came into being in October 1960 and has been adopted by nearly all countries, though the amount of actual usage varies considerably. This page is by no means complete, and only covers the most common units of measure. Also, liters and meters are spelled with the E and R purposely transposed, as spelled in metric countries -- litres and metres.

Choose a Calculator: Length | Weight | Pressure | Volume | Power | Astronomical Distance | Area | Speed | Force | Fuel Consumption | Energy | Temperature | Date

Date Calculator

Enter a date in the fields provided, and this calculator will tell you how many years and days since or before the provided date. Enter only numbers.

Prefixes of the SI

The SI allows the sizes of units to be made bigger or smaller by the use of appropriate prefixes. For example, the cycle unit of a hertz [hz] is not a big unit in terms of ordinary computer speed, so it is generally used in terms of 1,000,000 hertz at a time. The prefix for 1,000,000 is mega, so we use megahertz [Mhz] as our unit of measurement. For your computer, it is common to use megahertz [Mhz] to describe the speed of the Central Processing Unit (CPU). A 200 Mhz CPU runs at 200 million cycles. When talking about your hard drive, bytes [B] are used, and common prefixes for hard drives are mega [M], giga [G], and even terra [T]. A 4.3 gigabyte [GB] hard drive can store roughly 4 billion, 300 million bytes of data, while a 2 terrabyte [TB] disk array could store 2 trillion bytes of data. That's a lot of space! The full range of prefixes with their symbols (or abbreviations) and their multiplying factors which are also given in other forms:

A Brief History of Measurement

One of the earliest types of measurement concerned that of length. These measurements were usually based on parts of the body. A well documented example (the first) is the Egyptian cubit which was derived from the length of the arm from the elbow to the outstretched finger tips. By 2500 BC this had been standardized in a royal master cubit made of black marble (about 52 cm). This cubit was divided into 28 digits (roughly a finger width) which could be further divided into fractional parts, the smallest of these being only just over a millimetre.

In England, units of measurement were not properly standardized until the 13th century, though variations (and abuses) continued until long after that. For example, there were three different gallons (ale, wine and corn) up until 1824 when the gallon was standardized.

In the US the system of weights and measured first adopted was that of the English, though a few differences came in when decisions were made at the time of standardization in 1836. For instance, the wine-gallon of 231 cubic inches was used instead of the English one (as defined in 1824) of about 277 cubic inches. The US also took as its standard of dry measure from the old Winchester bushel of 2150.42 cubic inches, which gave a dry gallon nearly 269 cubic inches.

Even as late as the middle of the 20th century there were some differences in UK and US measures which were nominally the same. The UK inch measured 2.53998 cm while the US inch was 2.540005 cm. Both were standardized at 2.54 cm in July 1959, though the US continued to use its 2.540005 value for several years in land surveying work - this too is slowly being metricated.

In France the metric system officially started in June 1799 with the declared intent of being 'For all people, for all time'. The unit of length was the metre which was defined as being one ten-millionth part of a quarter of the earth's circumference. The production of this standard required a very careful survey to be done which took several years. However, as more accurate instruments became available so the 'exactness' of the standard was called into question. Later efforts were directed at finding some absolute standard based on an observable physical phenomenon. Over two centuries this developed into the SI. So maybe their original slogan was more correct than anyone could have foreseen then.

The US System of Measurements

Most of the US system of measurements is the same as that for the UK. The biggest differences to be noted are in Capacity which has both liquid and dry measures as well as being based on a different standard - the US liquid gallon is smaller than the UK gallon. There is also a measurement known as the US survey foot. It is gradually being phased out as the maps and land plans are re-drawn under metrication. (The changeover is being made by putting 39.37 US survey feet equal to 12 metres)