Weight Calculator
This calculator can convert values between the common weight and mass units.
Common Weight
| Milky Way Galaxy | 1.15357 x 1042 kg or 5.8 x 1011 solar mass |
| Sun | 1.9891x1030 kg |
| Earth | 5.9736 x 1024 kg |
| Moon | 7.3477 x 1022 kg |
| Atomic Mass Unit (u) | 1.660?538?782(83) x 10-27 kg |
| Neutron | 1.67492729(28) x 10-27 kg or 1.0086649156(6) u |
| Proton | 1.672621637(83) x 10-27 kg or 1.00727646677(10) u |
| Electron | 9.10938215(45) x 10-31 kg or 5.4857990943(23)x10-4 u |
Why We Have Different Ways to Measure Weight?
Ancient records from Babylon and Egypt, together with biblical passages, show that people first gauged weight by the volume of vessels—gourds, clay pots or metal bowls. They would fill them with counted seeds to estimate capacity. When balance scales appeared, seeds and stones became reference weights; the term ‘carat’ for gemstones still traces back to the carob seed.
The Babylonians invented the talent, as the basic unit of weight, and, based on their sexagesimal (60-based), divided into equal parts in terms of that number.
It was equal to the amount of water that filled an amphora (a kind of vase).
The Greeks inherited the Babylonian system of weighing, but the Romans revamped it. Their principal unit, the *uncia*, gave rise to the English word ‘ounce’. An *uncia* represented one‑twelfth of the Roman *pes* (foot), and from this the word ‘inch’ also originated. The Romans adopted the same designation for an ounce, employing a weighing method they had taken over from the Arab tradition.
In Arab metrology a silver Dirhem was defined as 45 mature barley kernels. Ten Dirhems formed a wukryeh of 450 kernels, a quantity that later became known in Latin as an ‘uncia’—the ancestor of the modern ounce, a term used for that class of weight or volume.
When the term ‘ounce’ entered English, King Offa of the late 8th century endorsed the silver ounce but soon faced a shortage of metal. He therefore split the Dirhem to 222 grains for a penny; twenty such pennies still equaled an ounce, and twelve ounces constituted a pound of silver.
This definition survived as a component of the British Imperial system of weights and measures, which the United States also inherited. The framework was first codified in the British Weights and Measures Act of 1824, later tweaked, and eventually imposed throughout the British Empire.
A disastrous fire in 1855 razed the Houses of Parliament, destroying the original weight standards. In response, a standards bureau was established, producing new prototype artifacts for the imperial system.
Metric units have a separate lineage. The gram and kilogram were devised by French scientists during the late 1700s. In 1791 the French legislature mandated the metric system nationwide; today it is the standard across continental Europe and numerous other regions.
The metric system was not particularly popular in revolutionary France, and Emperor Napoleon, who came just after the Revolution, abolished it. But, when Napoleon lost power, the system was reinstated.
One kilogram corresponds to the mass of a litre of water, while a gram is one‑thousandth of that. All derived multiples and sub‑multiples follow powers of ten, so fractional units are expressed in tenths rather than halves, unlike the customary inch system. This decimal base simplifies conversion between units.
Here are some typical metric conversions:
- 1 milliliter is the same volume as 1 cubic centimeter.
- The mass of 1 milliliter of water is approximately 1 gram.
- The mass of 1 liter of water is therefore approximately 1 kilogram.
- There are 1000 liters in a cubic meter, so the mass of 1 cubic meter of water is approximately 1000 kilograms or 1 metric ton.
- A US nickel weighs 5 grams, and a penny weighs 2.5 grams.
- Although there's no precise standard for doorknob heights, they're often about 1 meter above the floor.
- A compact disc or DVD measures 12 cm (120 mm) in diameter, with a central hole 15 mm wide.
- One hectare equals 10,000 m², the area of a 100 m × 100 m square. Since a typical football pitch is about 100 m long, picture a square whose each side matches that length—that's one hectare.