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What Is a Weight Converter?

A weight converter is a free online tool that instantly converts any measurement of weight or mass between all major metric and imperial units — kilograms, pounds, ounces, grams, stones, milligrams, metric tons, short tons, long tons, and more — with complete accuracy and no manual arithmetic required.

The Anchor Conversion — Foundation of All Weight Conversions

The internationally standardised exact conversion between the avoirdupois pound and the kilogram — fixed in 1959:

1 pound = 0.45359237 kilograms exactly

All other imperial-to-metric weight conversions are derived from this single anchor:

Key Conversion Factors at a Glance

FromToMultiply By
Kilograms (kg)Pounds (lb)× 2.20462
Pounds (lb)Kilograms (kg)× 0.453592
Kilograms (kg)Ounces (oz)× 35.27396
Ounces (oz)Grams (g)× 28.34952
Grams (g)Ounces (oz)× 0.035274
Stones (st)Kilograms (kg)× 6.350293
Kilograms (kg)Stones (st)× 0.157473
Stones (st)Pounds (lb)× 14
Troy ouncesGrams (g)× 31.10348
Carats (ct)Grams (g)× 0.2

Kilograms to Pounds — Quick Reference

KilogramsPoundsStones & Pounds
50 kg110.2 lb7 st 12.2 lb
60 kg132.3 lb9 st 6.3 lb
70 kg154.3 lb11 st 0.3 lb
75 kg165.3 lb11 st 9.3 lb
80 kg176.4 lb12 st 8.4 lb
90 kg198.4 lb14 st 2.4 lb
100 kg220.5 lb15 st 10.5 lb
120 kg264.6 lb18 st 12.6 lb

Understanding Stones — The Uniquely British Weight Unit

The stone is a unit of weight used almost exclusively in the United Kingdom and Ireland for expressing human body weight in everyday speech. It is not used in any other country and is not part of either the metric system or the formal US customary system.

Definition: 1 stone = 14 pounds = 6.35029 kilograms

A British person who weighs 76 kilograms would typically say they weigh "12 stone" in everyday conversation — or more precisely "11 stone 13 pounds" (since 76 kg = 167.55 lb = 11 st 13.55 lb).

The Three Types of "Ton" — Clearing the Confusion

Ton TypePoundsKilogramsCompared to Metric Ton
Short ton (US)2,000 lb907.185 kg9.3% lighter
Metric ton (tonne)2,204.623 lb1,000.000 kgBaseline
Long ton (UK)2,240 lb1,016.047 kg1.6% heavier

The Avoirdupois, Troy, and Apothecary Systems

Avoirdupois System — Everyday Imperial

Used for all everyday commercial weight — food, body weight, freight. 16 ounces = 1 pound, 14 pounds = 1 stone, 2,000 pounds = 1 short ton.

Troy System — Precious Metals

Used exclusively for precious metals (gold, silver, platinum). 1 troy ounce = 31.1035 grams (heavier than the avoirdupois ounce of 28.3495 grams). 1 troy pound = 373.242 grams (lighter than the avoirdupois pound of 453.592 grams — because a troy pound contains only 12 troy ounces while an avoirdupois pound contains 16 smaller ounces).

Grams to Ounces — Cooking Reference

GramsOuncesCommon Equivalent
28g1 ozStandard serving reference
100g3.527 ozCommon nutrition label size
113g4 oz (¼ lb)Quarter pound burger
227g8 oz (½ lb)Half pound
250g8.818 ozCommon recipe measurement
454g16 oz (1 lb)One pound
500g17.637 ozHalf kilogram
1000g35.274 oz (2.205 lb)One kilogram

Frequently Asked Questions (FAQ)

Q: Is the weight converter completely free?

Yes. This online weight converter is 100% free with no registration, no subscription, and no payment required. Convert as many measurements as you need, as often as you need them.

Q: How many pounds are in a kilogram?

One kilogram equals exactly 2.20462 pounds. Equivalently, one pound equals exactly 0.45359237 kilograms — the internationally standardised exact conversion factor fixed in 1959. For quick mental estimation: 1 kg ≈ 2.2 lb and 1 lb ≈ 0.45 kg.

Q: How many grams are in an ounce?

One avoirdupois ounce equals exactly 28.349523125 grams. One troy ounce — used for precious metals — equals 31.1034768 grams. When a recipe calls for ounces, it always means avoirdupois ounces (28.35g). When gold or silver prices quote "per ounce," they always mean troy ounces (31.10g).

Q: What is a stone in kilograms?

One stone equals exactly 14 pounds or 6.35029318 kilograms. To convert stones to kilograms, multiply the number of stones by 6.35029. The stone is used almost exclusively in the United Kingdom and Ireland for expressing human body weight in everyday speech.

Q: What is the difference between a short ton and a metric ton?

A short ton (the American ton) equals 2,000 pounds or 907.185 kilograms. A metric ton (tonne) equals exactly 1,000 kilograms or 2,204.623 pounds. A metric ton is approximately 10% heavier than a short ton. A long ton (the British ton) equals 2,240 pounds or 1,016.047 kilograms.

Q: How do I convert pounds to kilograms quickly in my head?

The most useful mental math shortcut: divide pounds by 2.2 to get kilograms. For example, 154 pounds ÷ 2.2 = 70 kg. For the reverse, multiply kilograms by 2.2: 70 kg × 2.2 = 154 pounds. This gives a result accurate to within about 0.09%.

Q: What is a troy ounce and how does it differ from a regular ounce?

A troy ounce (31.1035g) is the unit used for trading precious metals — gold, silver, platinum, palladium. It is approximately 10% heavier than the avoirdupois ounce (28.3495g) used for everyday weights. When you see the price of gold quoted per ounce, it is always per troy ounce.

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