Mass / Weight Converter

Convert between kilograms, grams, pounds, ounces, stones, tons and every other unit of mass, from the electron to the Sun, including troy, apothecaries' and historical weights.

1 kilogram = 2.204622622 pounds

Most used weight units

Popular weight conversions

What is weight?

Mass is the amount of matter in an object. Weight, strictly, is the force that gravity exerts on that mass, but in everyday language (and on every bathroom scale and grocery label) the two words mean the same thing, and both are measured in kilograms, pounds and the other units on this page.

The SI unit of mass is the kilogram. Since 2019 it has been defined by fixing the value of the Planck constant, replacing the platinum-iridium cylinder that served as the world's reference from 1889. The pound used in the United States and the United Kingdom is defined as exactly 0.45359237 kg.

Several systems of weights are still in use side by side: the everyday avoirdupois system (ounces, pounds, stones), the troy system for precious metals, the carat for gemstones, and the dalton for atoms and molecules. Because an ounce or a pound means different amounts in different systems, each has its own page here.

Common weight equivalents

  • 1 kilogram = 1,000 grams ≈ 2.20462 pounds
  • 1 pound = 16 ounces = 453.59237 grams exactly
  • 1 ounce = 28.349523125 grams exactly
  • 1 stone = 14 pounds ≈ 6.35 kg
  • 1 US (short) ton = 2,000 pounds ≈ 907.2 kg
  • 1 metric ton (tonne) = 1,000 kg ≈ 2,204.6 pounds
  • 1 troy ounce ≈ 31.1035 grams, about 10% heavier than an ordinary ounce
  • 1 carat = 200 milligrams exactly

Mass or weight?

Your mass is the same everywhere; your weight depends on gravity. An astronaut with a mass of 80 kg still has a mass of 80 kg on the Moon, but weighs only about one sixth as much there, because lunar gravity is about 1.62 m/s² compared with 9.81 m/s² on Earth.

Scales actually measure weight (a force) and then convert it to mass assuming Earth's gravity. Physicists measure force in newtons; see the force converter for units such as the pound-force and kilogram-force.

A short history of weights

The earliest standards of weight were seeds and grains: the carat comes from the carob seed and the grain from a grain of wheat or barley. Ancient Mesopotamia built a system of shekels, minas and talents that spread across the Mediterranean, and Roman weights, the libra and uncia, gave us the abbreviation "lb" and the word "ounce".

The kilogram was introduced in revolutionary France as the mass of a liter of water. The international prototype kilogram, a platinum-iridium cylinder kept near Paris, defined it from 1889 until 2019, when the kilogram was redefined through the Planck constant so that it no longer depends on a single physical object.

Weight units from smallest to largest

Every proportional weight unit on the site, ordered by size and expressed in kilograms.

  1. Electronvolt per c² 1.782662 × 10-36 kg
  2. Electron mass 9.109384 × 10-31 kg
  3. Megaelectronvolt per c² 1.782662 × 10-30 kg
  4. Muon mass 1.883532 × 10-28 kg
  5. Dalton 1.660539 × 10-27 kg
  6. Proton mass 1.672622 × 10-27 kg
  7. Neutron mass 1.674927 × 10-27 kg
  8. Gigaelectronvolt per c² 1.782662 × 10-27 kg
  9. Kilodalton 1.660539 × 10-24 kg
  10. Picogram 1 × 10-15 kg
  11. Nanogram 1 × 10-12 kg
  12. Microgram 1 × 10-9 kg
  13. Gamma 1 × 10-9 kg
  14. Planck mass 2.176434 × 10-8 kg
  15. Milligram 0.000001 kg
  16. Point 0.000002 kg
  17. Mite 0.00000323995 kg
  18. Centigram 0.00001 kg
  19. Grain of rice 0.000025 kg
  20. Japanese rin (mass) 0.0000375 kg
  21. Dolya 0.00004443 kg
  22. Babylonian grain 0.0000463 kg
  23. Portuguese grain 0.0000498 kg
  24. Spanish grain 0.0000499 kg
  25. Pearl grain 0.00005 kg
  26. Chinese li (mass) 0.00005 kg
  27. French grain 0.000053115 kg
  28. Grain 0.0000647989 kg
  29. Decigram 0.0001 kg
  30. Ratti 0.0001215 kg
  31. Siliqua 0.000189 kg
  32. Carat 0.0002 kg
  33. Fun 0.000375 kg
  34. Chinese fen (mass) 0.0005 kg
  35. Roman obol 0.000568 kg
  36. Gerah 0.00057 kg
  37. Greek obol 0.00072 kg
  38. Masha 0.000972 kg
  39. Gram 0.001 kg
  40. Paperclip 0.001 kg
  41. Scrupulum 0.001137 kg
  42. Scruple 0.00129598 kg
  43. Pennyweight 0.00155517 kg
  44. Dram 0.00177185 kg
  45. Adarme 0.001797 kg
  46. US penny 0.0025 kg
  47. Dirham 0.003207 kg
  48. Oitava 0.003586 kg
  49. Vietnamese chi 0.00375 kg
  50. Monme 0.00375 kg
  51. Don 0.00375 kg
  52. Salueng 0.00375 kg
  53. Hong Kong mace 0.00377994 kg
  54. Gros 0.0038242 kg
  55. Apothecaries' dram 0.00388793 kg
  56. Mithqal 0.00425 kg
  57. Zolotnik 0.0042658 kg
  58. Drachma 0.00431 kg
  59. Sextula 0.00455 kg
  60. Qian 0.005 kg
  61. US nickel 0.005 kg
  62. Bekah 0.0057 kg
  63. Pim 0.0076 kg
  64. Babylonian shekel 0.00833 kg
  65. Kite 0.0091 kg
  66. Decagram 0.01 kg
  67. Biblical shekel 0.0114 kg
  68. Tola 0.0116638 kg
  69. Russian lot 0.012797 kg
  70. Baht (weight) 0.015 kg
  71. Thai baht (gold) 0.015244 kg
  72. German lot 0.015625 kg
  73. Roman ounce 0.02729 kg
  74. Ounce 0.0283495 kg
  75. Portuguese ounce 0.02869 kg
  76. Onza 0.0287558 kg
  77. German ounce 0.0292 kg
  78. French ounce 0.030594 kg
  79. Troy ounce 0.0311035 kg
  80. Apothecaries' ounce 0.0311035 kg
  81. Vietnamese luong 0.0375 kg
  82. Taiwan tael 0.0375 kg
  83. Nyang 0.0375 kg
  84. Hong Kong tael 0.0377994 kg
  85. Tahil 0.0378 kg
  86. Liang 0.05 kg
  87. Chhatak 0.058319 kg
  88. Tamlueng 0.06 kg
  89. Deben 0.091 kg
  90. Hectogram 0.1 kg
  91. Metric ounce 0.1 kg
  92. Banana 0.12 kg
  93. Apple 0.18 kg
  94. Big Mac 0.219 kg
  95. Cologne mark 0.2338 kg
  96. Roman pound 0.3275 kg
  97. Troy pound 0.373242 kg
  98. Apothecaries' pound 0.373242 kg
  99. Ratl 0.4068 kg
  100. Funt 0.409512 kg
  101. Swedish pound 0.4251 kg
  102. Greek mina 0.431 kg
  103. Pound 0.453592 kg
  104. Arratel 0.459 kg
  105. Castilian pound 0.4601 kg
  106. Livre 0.4895 kg
  107. Amsterdam pound 0.494 kg
  108. Metric pound 0.5 kg
  109. Babylonian mina 0.5 kg
  110. Jin 0.5 kg
  111. Biblical mina 0.571 kg
  112. Taiwan catty 0.6 kg
  113. Kin 0.6 kg
  114. Geun 0.6 kg
  115. Vietnamese can 0.6045 kg
  116. Hong Kong catty 0.60479 kg
  117. Kati 0.60479 kg
  118. Seer 0.9331 kg
  119. Kilogram 1 kg
  120. Chang 1.2 kg
  121. Okka 1.2829 kg
  122. Kan 3.75 kg
  123. Gwan 3.75 kg
  124. Stone 6.35029 kg
  125. Bowling ball 7.257 kg
  126. Lispund 8.502 kg
  127. Metric slug 9.80665 kg
  128. Spanish arroba 11.502 kg
  129. Gold bar 12.4413 kg
  130. Quarter 12.7006 kg
  131. Slug 14.5939 kg
  132. Portuguese arroba 14.688 kg
  133. Brazilian arroba 15 kg
  134. Pood 16.3805 kg
  135. Attic talent 25.86 kg
  136. Babylonian talent 30 kg
  137. Roman talent 32.7 kg
  138. Biblical talent 34.2 kg
  139. Maund 37.3242 kg
  140. Kantar 44.928 kg
  141. Short hundredweight 45.3592 kg
  142. Spanish quintal 46.0093 kg
  143. French quintal 48.95 kg
  144. Dan 50 kg
  145. Zentner 50 kg
  146. Long hundredweight 50.8023 kg
  147. Portuguese quintal 58.752 kg
  148. Hap 60 kg
  149. Picul 60.479 kg
  150. Adult human 62 kg
  151. Quintal 100 kg
  152. Berkovets 163.805 kg
  153. Skeppund 170.03 kg
  154. Blob 175.127 kg
  155. Kip 453.592 kg
  156. Horse 500 kg
  157. Short ton 907.185 kg
  158. Tonelada 920.186 kg
  159. Tonne 1,000 kg
  160. Long ton 1,016.05 kg
  161. Honda Civic 1,350 kg
  162. Average car 1,500 kg
  163. African elephant 6,000 kg
  164. Blue whale 150,000 kg
  165. Boeing 747 180,000 kg
  166. Statue of Liberty 204,000 kg
  167. Kilotonne 1,000,000 kg
  168. Eiffel Tower 10,100,000 kg
  169. Titanic 52,310,000 kg
  170. Megatonne 1,000,000,000 kg
  171. Gigatonne 1,000,000,000,000 kg
  172. Moon mass 7.342 × 1022 kg
  173. Earth mass 5.9722 × 1024 kg
  174. Jupiter mass 1.89813 × 1027 kg
  175. Solar mass 1.98847 × 1030 kg

All 175 weight units

Metric (SI)

Avoirdupois (US & imperial)

Troy & apothecaries'

Gem & precious metal

Engineering

Atomic & physics

Astronomical

Ancient

East & Southeast Asian

South Asian & Middle Eastern

European (pre-metric)

Everyday comparisons

Frequently asked questions

What is the SI unit of mass?

The kilogram (kg). Since 2019 it has been defined by fixing the Planck constant at exactly 6.62607015 × 10⁻³⁴ J·s.

How many pounds are in a kilogram?

One kilogram is about 2.20462 pounds. One pound is exactly 0.45359237 kilograms.

How many grams are in an ounce?

An ordinary (avoirdupois) ounce is exactly 28.349523125 grams. A troy ounce, used for gold and silver, is 31.1034768 grams.

What is the difference between a ton and a tonne?

A US ton (short ton) is 2,000 pounds (907.18 kg). A tonne (metric ton) is 1,000 kg (2,204.6 lb). A UK long ton is 2,240 pounds (1,016 kg).

How many pounds are in a stone?

Exactly 14 pounds, or about 6.35 kilograms. The stone is used for body weight in the UK and Ireland.

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