Unit Converter
Convert between 100+ units across 11 categories — length, weight, temperature, area, volume, speed, time, digital storage, energy, pressure, and angle. Instant results with formula explanations and full conversion tables.
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Weight Converter
Convert weight and mass between 17 units — micrograms, milligrams, grams, kilograms, metric tonnes, ounces, pounds, stones, short tons, long tons, carats, troy ounces, and more. Instant results with formula and full reference table.
Common Conversions
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Explore This Tool in Context
Weight Converter is part of the Conversion Tools collection. If you want a broader view of similar workflows, open the Conversion Tools category page or browse all QuickTools categories.
Common next steps after this tool include Unit Converter, Length Converter and Temperature Converter.
What Is a Weight Converter?
A weight converter is an online tool that instantly transforms any measurement of weight or mass from one unit to another — no arithmetic required. Whether you need to convert kilograms to pounds for a recipe, grams to ounces for a shipping label, or metric tonnes to short tons for an industrial order, this tool covers every everyday and specialist use case.
It supports 17 units across three systems: the metric (SI) system from micrograms to kilotonnes, the imperial/US customary system from grains to long tons, and the troy system used in precious-metal and gemstone trading. All conversion factors are the exact internationally-defined values, stored at full floating-point precision.
How to Use the Weight Converter
- Quick conversions — tap one of the shortcut chips (kg→lb, lb→kg, oz→g, etc.) to pre-fill the most common pairs instantly.
- Choose units manually — use the From and To dropdowns, which are grouped by system (Metric, Imperial/US, Troy).
- Enter a value — type any number in the input field; the result updates live as you type.
- Swap direction — click ⇄ to reverse the conversion and reuse the result as the new input.
- Copy the result — hit the Copy button to copy the converted value to your clipboard.
- Browse all conversions — the All Conversions table shows your value in every unit at once. Use the group tabs (All / Metric / Imperial / Troy) to filter, or click any row to set that unit as the new target.
Common Weight Conversion Examples
| From | To | Result | Common Use |
|---|---|---|---|
| 1 kilogram | pounds | 2.20462 lb | Body weight, food |
| 1 pound | kilograms | 0.453592 kg | Body weight, food |
| 1 ounce | grams | 28.3495 g | Cooking, shipping |
| 100 grams | ounces | 3.52740 oz | Cooking, nutrition |
| 1 stone | kilograms | 6.35029 kg | UK body weight |
| 1 stone | pounds | 14 lb | UK body weight |
| 1 metric tonne | pounds | 2,204.62 lb | Industry, cargo |
| 1 metric tonne | short tons (US) | 1.10231 ton | Industry, agriculture |
| 1 troy ounce | grams | 31.1035 g | Gold, silver prices |
| 1 carat | grams | 0.2 g | Diamond & gem weight |
| 70 kg | pounds | 154.324 lb | Body weight |
| 500 grams | ounces | 17.6370 oz | Cooking, baking |
How the Weight Converter Works
Every unit of weight is stored as an exact multiplier relative to the kilogram (the SI base unit). To convert from unit A to unit B, the calculator uses a two-step ratio:
result = value × factor(A) ÷ factor(B)
For example, to convert 5 pounds → grams: 1 pound = 0.45359237 kg, 1 gram = 0.001 kg, so result = 5 × 0.45359237 ÷ 0.001 = 2267.96 g.
All factors are exact internationally-defined values (e.g. 1 pound = 0.45359237 kg exactly per the 1959 International Yard and Pound Agreement; 1 carat = 0.0002 kg exactly). Results are rounded to 10 significant figures to eliminate floating-point noise while preserving full scientific precision.
Weight Unit Reference
⚗️Metric (SI)
- µgMicrogram— Drug dosing, lab science
- mgMilligram— Medication, nutrition labels
- gGram— Cooking, everyday items
- kgKilogram— SI base unit of mass
- qQuintal— 100 kg, agriculture
- tMetric Tonne— 1,000 kg, industry/cargo
- ktKilotonne— 1,000 tonnes, bulk tonnage
🏋️Imperial / US Customary
- grGrain— 64.799 mg, gunpowder/ammo
- ozOunce (avoirdupois)— 28.3495 g, cooking/shipping
- lbPound— 0.453592 kg, everyday weight
- stStone— 14 lb, UK body weight
- cwtHundredweight (US)— 100 lb, commodity trading
- tonShort Ton (US)— 2,000 lb, US industry
- LTLong Ton (UK)— 2,240 lb, UK industry/shipping
💎Troy / Precious Metals
- ctCarat— 0.2 g exactly, gem weight
- oztTroy Ounce— 31.1035 g, gold/silver prices
- lbtTroy Pound— 12 troy oz, precious metals
Frequently Asked Questions
How many pounds are in a kilogram?+
Exactly 2.20462262 pounds. This comes from the exact definition: 1 pound = 0.45359237 kg (1959 international agreement). So 1 kg ÷ 0.45359237 = 2.20462262 lb.
What is the difference between a troy ounce and a regular ounce?+
A troy ounce (ozt) = 31.1035 grams, while an avoirdupois ounce (oz) = 28.3495 grams. Troy ounces are about 10% heavier and are used exclusively for precious metals (gold, silver, platinum) and gemstones.
How many ounces are in a pound?+
Exactly 16 avoirdupois ounces. This is an exact definition: 1 lb = 16 oz. Note that this refers to regular (avoirdupois) ounces, not troy ounces — a troy pound has 12 troy ounces.
How do I convert stone to kg?+
Multiply the number of stones by 6.35029318. For example, 11 stone = 11 × 6.35029 = 69.85 kg. One stone equals exactly 14 pounds = 6.35029318 kg.
What is a carat and why is it used for diamonds?+
A metric carat = exactly 0.2 grams (200 milligrams). It is the standard unit for measuring the weight of diamonds and other gemstones. The name comes from the carob seed, which was historically used as a reference weight. A 1-carat diamond weighs 0.2 g.
What is the difference between a US short ton and a UK long ton?+
A US short ton = 2,000 pounds (907.185 kg). A UK long ton = 2,240 pounds (1,016.05 kg). The metric tonne = 1,000 kg ≈ 2,204.62 lb, which falls between the two. Always clarify which 'ton' is meant in international trade.
Is this converter accurate for scientific or pharmaceutical use?+
Yes. All conversion factors are stored at full IEEE 754 double-precision accuracy using exact internationally-defined values. Results are displayed to 10 significant figures, exceeding the precision required for pharmaceutical, nutritional, and engineering applications.
How do I convert grams to pounds and ounces?+
First convert grams to total ounces (divide by 28.3495). Then: whole pounds = floor(total oz ÷ 16), remaining oz = total oz mod 16. Example: 500 g ÷ 28.3495 = 17.637 oz = 1 lb 1.637 oz.
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