Weight Converter

Convert weight or mass between milligrams, grams, kilograms, metric tonnes, ounces, pounds, stone, short tons, and long tons, with all equivalents shown at once including the stone-and-pounds composite.

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Weight & Mass

Convert weight between metric and imperial units

Enter a weight in any unit — milligrams through metric tonnes and ounces through long tons. All equivalents are shown at once, including the stone-and-pounds composite used for body weight in the UK.

Metric

Milligrams 70,000,000 mg
Grams 70,000 g
Kilograms 70 kg
Metric tonnes 0.07 t

Imperial

Ounces 2,469.18 oz
Pounds 154.324 lb
Stone 11.0231 st
Short tons (US) 0.0772 short ton
Long tons (UK) 0.0689 long ton
Stone & pounds 11 st 0.3 lb

Quick reference

  • 1 oz = 28.3495 g
  • 1 lb = 453.592 g
  • 1 st = 14 lb = 6.350 kg
  • 1 kg ≈ 2.20462 lb
  • 1 short ton = 2,000 lb ≈ 907 kg
  • 1 long ton = 2,240 lb ≈ 1,016 kg

Weight & Mass

Weight conversion: kilograms, pounds, stone, ounces, and tonnes explained

A weight converter translates any mass or weight value into all common units simultaneously. This tool covers milligrams, grams, kilograms, metric tonnes, ounces, pounds, stone, short tons, and long tons — plus the stone-and-pounds composite used for body weight in the UK and Ireland.

Metric and imperial weight units compared

The metric system bases all mass units on the kilogram, the SI base unit. One gram is one thousandth of a kilogram; one tonne is one thousand kilograms. Conversion is straightforward multiplication by powers of ten. The imperial and US customary systems use a different set of units: 16 ounces in a pound, 14 pounds in a stone, 2,000 pounds in a US short ton, and 2,240 pounds in a UK long ton.

The fundamental conversion is exact: one pound equals exactly 0.45359237 kg (adopted 1959). From that, one ounce equals 0.028349523125 kg, one stone equals 6.35029318 kg, one US short ton equals 907.18474 kg, and one UK long ton equals 1016.0469088 kg.

The stone-and-pounds composite

In the UK and Ireland, body weight is commonly expressed as a stone-and-pounds composite — for example, "11 stone 4 pounds" rather than "158 lb" or "71.7 kg". One stone equals 14 pounds. To convert a decimal stone value to the composite, take the integer part as whole stones and multiply the remainder by 14 to get the pounds.

This tool handles both directions. Enter a value in any single unit and you get the stone-and-pounds composite alongside all metric values. Or enter stone and pounds separately to get the metric equivalents.

Short tons vs long tons

Two different "tons" are in common use. The short ton (US ton) equals 2,000 pounds or approximately 907 kg — used in the United States for commercial and shipping purposes. The long ton (UK ton) equals 2,240 pounds or approximately 1,016 kg — used historically in the UK and in some international shipping contexts. Both differ from the metric tonne (1,000 kg = 2,205 lb).

When a weight is stated in "tons" without further qualification, context usually determines which is meant: US documents typically use short tons; UK shipping and older British documents often use long tons; scientific and international trade documents use metric tonnes.

Common uses: body weight, cooking, postage, and freight

Body weight: kg worldwide; lb in the US; st and lb in the UK and Ireland. BMI uses weight in kilograms and height in metres — this converter gives you the kg value from any input format. Cooking: recipes may use grams, ounces, or pounds. Postage and parcels: services list maximum weights in kg or lb depending on country.

Freight and bulk materials: metric tonnes are standard internationally; short tons are common in US freight; long tons appear in maritime and bulk shipping. For any of these contexts, enter your known value and unit to see all equivalents at once.

Frequently asked questions

How many kilograms are in a pound?

One pound equals exactly 0.45359237 kilograms. Equivalently, one kilogram equals approximately 2.20462 pounds. The factor is exact because the pound was redefined as exactly 0.45359237 kg in 1959 by international agreement.

 What is the difference between a metric tonne, a short ton, and a long ton?

A metric tonne = 1,000 kg = 2,204.62 lb. A short ton (US) = 2,000 lb ≈ 907.2 kg. A long ton (UK) = 2,240 lb ≈ 1,016.0 kg. The three are close but not equal — a long ton is about 12% heavier than a short ton, and the metric tonne sits between them.

 How do I convert stone and pounds to kilograms?

Multiply the stone value by 14 to get total pounds, then multiply by 0.45359237. For example, 11 st 4 lb = (11 × 14 + 4) = 158 lb × 0.45359237 ≈ 71.67 kg. Alternatively, use this converter — enter your stone and pounds, select "Stone & Pounds" mode, and all metric equivalents are shown instantly.

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