Weight Unit Converter

How to use this calculator

Enter a weight amount. Select the unit you are converting from. Press Calculate to see all weight equivalents: grams, kilograms, milligrams, ounces, pounds, stone, metric tonnes, and troy ounces.

Weight unit conversion factors

All units convert through grams as the base. The exact definitions:

Unit	Grams Equivalent	Notes
1 Milligram (mg)	0.001 g	1/1000 of a gram
1 Gram (g)	1 g	Metric base unit
1 Kilogram (kg)	1000 g	1000 grams
1 Metric Tonne (t)	1,000,000 g	1000 kg
1 Ounce (oz, avoirdupois)	28.3495 g	Everyday use
1 Pound (lb)	453.592 g	16 oz
1 Stone (st)	6350.29 g	14 lb, used in UK
1 US Short Ton	907,185 g	2000 lb
1 UK Long Ton	1,016,050 g	2240 lb
1 Troy Ounce (ozt)	31.1035 g	Precious metals
1 Troy Pound (lbt)	373.242 g	12 troy oz

Metric vs imperial weight system

The metric system (grams, kilograms, tonnes) and the imperial system (ounces, pounds, stone, tons) are the two major weight measurement frameworks. Most countries use metric; the US, UK (partially), and a few others retain imperial units in everyday use.

Metric system hierarchy: 1 tonne = 1000 kg = 1,000,000 g = 1,000,000,000 mg

Everything multiplies or divides by 1000. This makes metric conversion simple: move the decimal point.

Imperial/US system hierarchy: 1 long ton (UK) = 2240 lb = 35840 oz 1 short ton (US) = 2000 lb = 32000 oz 1 stone = 14 lb = 224 oz 1 pound = 16 oz 1 ounce = 28.35 g

The imperial hierarchy uses irregular factors (16, 14, 2000, 2240), which is why mental conversion is harder than with metric.

Cross-system anchors to memorise:

• 1 kg = 2.2046 lb (approximately 2.2 lb)
• 1 lb = 453.6 g (approximately 454 g or 0.454 kg)
• 1 oz = 28.35 g (approximately 28 g)
• 100 g = 3.527 oz (approximately 3.5 oz)

Grams, kilograms, and milligrams conversion table

Quick reference for metric-to-metric and metric-to-imperial conversions:

Grams (g)	Kilograms (kg)	Milligrams (mg)	Ounces (oz)	Pounds (lb)
0.1 g	0.0001 kg	100 mg	0.0035 oz	0.00022 lb
1 g	0.001 kg	1000 mg	0.03527 oz	0.002205 lb
10 g	0.01 kg	10,000 mg	0.353 oz	0.02205 lb
28.35 g	0.02835 kg	28,350 mg	1 oz	0.0625 lb
100 g	0.1 kg	100,000 mg	3.527 oz	0.2205 lb
250 g	0.25 kg	250,000 mg	8.818 oz	0.5512 lb
453.6 g	0.4536 kg	453,592 mg	16 oz	1 lb
500 g	0.5 kg	500,000 mg	17.637 oz	1.1023 lb
1000 g	1 kg	1,000,000 mg	35.274 oz	2.2046 lb
2000 g	2 kg	2,000,000 mg	70.548 oz	4.409 lb

Stone: the UK body weight unit

The stone is used in the United Kingdom and Ireland as a unit of body weight. It is not used in the US, Australia, or most other countries.

1 stone = 14 pounds = 6.350 kg

Common stone-to-kg conversions for body weight:

Stone	Pounds	Kilograms
7 st	98 lb	44.45 kg
8 st	112 lb	50.80 kg
9 st	126 lb	57.15 kg
10 st	140 lb	63.50 kg
11 st	154 lb	69.85 kg
12 st	168 lb	76.20 kg
13 st	182 lb	82.55 kg
14 st	196 lb	88.90 kg
15 st	210 lb	95.25 kg
16 st	224 lb	101.60 kg

Mixed stone and pounds: UK residents often say a weight like “11 stone 4 pounds.” To convert: (11 x 14 + 4) x 0.453592 = 158 x 0.453592 = 71.67 kg.

Troy weight: ounces and pounds for precious metals

The troy system is used exclusively for precious metals (gold, silver, platinum, palladium) and gemstones.

Troy ounce (ozt) = 31.1035 g — about 10% heavier than the avoirdupois ounce (28.35 g)

Troy pound = 12 troy ounces = 373.242 g — lighter than the avoirdupois pound (453.6 g) because the troy pound has only 12 ounces, not 16.

This creates a counterintuitive situation: a troy ounce is heavier than a regular ounce, but a troy pound is lighter than a regular pound.

Why it matters: Gold prices are quoted in troy ounces. “1 oz of gold” in financial markets always means 1 troy oz = 31.1 g. If you calculated using 28.35 g, you would underestimate the gold mass by about 9.7%.

Practical use: When buying gold coins or bars, check whether the stated weight is in troy ounces or grams. A “1 oz” American Eagle gold coin contains 1 troy oz = 31.1 g of gold (plus alloying metals for hardness).

Tons: short ton, long ton, and metric tonne

Three different “ton” units exist:

Metric tonne (t) = 1000 kg = 2204.62 lb. Used in international trade, science, and most countries. Sometimes written “tonne” to distinguish from other ton variants.

US short ton = 2000 lb = 907.185 kg. Used in the United States for commercial weighing of goods like coal, steel, and grain. A “ton” in the US context usually means the short ton.

UK long ton = 2240 lb = 1016.05 kg. Used historically in the UK and British Commonwealth. The larger factor of 2240 comes from 160 stone (each of 14 lb). The long ton is rarely used today, mostly in historical or nautical contexts.

Ship tonnage is different. Gross tonnage for ships measures volume, not weight. “Deadweight tonnage” (DWT) is the weight of cargo a ship can carry, measured in metric tonnes.

Ton type	kg	lb	Origin
Metric tonne	1000 kg	2204.62 lb	International
US short ton	907.185 kg	2000 lb	United States
UK long ton	1016.05 kg	2240 lb	United Kingdom

Weight conversion in cooking and nutrition

Cooking uses grams and kilograms (metric countries) or ounces and pounds (US). Nutrition labels worldwide show grams.

Cooking reference points:

• A large egg without shell: approximately 50 g
• A standard US stick of butter: 113.4 g = 4 oz = 1/4 lb
• A pound of ground beef: 453.6 g (standard US packaging)
• A 500 g block of cheese: 17.6 oz = 1.1 lb
• A 1 kg bag of sugar: 2.205 lb = 35.27 oz = 5 US cups

Nutrition label conversions:

• Serving size “28 g” = 1 oz (common for snack foods)
• Serving size “85 g” = 3 oz (common for meat)
• “Per 100 g” values are the international standard for food composition

US food package sizes in grams:

• 1 lb (standard meat, butter) = 453.6 g
• 5 lb (flour, sugar bags) = 2268 g
• 2 oz (snack-size bags) = 56.7 g
• 16 oz can = 453.6 g (1 lb)
• 28 oz can = 793.8 g