Weight Converter

About this Weight Converter

The Weight Converter changes a mass value between frequently used metric and imperial units. It uses kilograms as the internal reference and applies standard factors for grams, milligrams, ounces, pounds and stone.

Mass and weight conversions between metric (kilograms, grams) and imperial (pounds, ounces) units come up constantly in shipping, cooking, fitness tracking and medical contexts, and small rounding differences can matter for postage costs and medication dosing.

For related tasks, try Calorie Calculator, Ser to KG Converter or Tola to Gram Converter.

How to use it

1. Enter the mass value.
2. Select the current unit.
3. Choose the unit you want and convert.

Practical example

One kilogram equals 1,000 grams and about 2.20462 pounds. Enter 1 kg and select pounds to see the equivalent.

A person weighing 70 kilograms converts to approximately 154.32 pounds, a benchmark figure commonly referenced when comparing metric and imperial body weight figures across fitness apps and medical records.

Things to double-check

This converter handles mass units, which stay constant regardless of location, unlike weight in the strict physics sense (the force gravity exerts on mass), which technically varies slightly by location; everyday usage treats weight and mass interchangeably, and this tool follows that common convention.

Common weight conversions

One kilogram is about 2.20462 pounds, one pound is 453.592 grams and one ounce is 28.3495 grams. A stone is 14 pounds, or 6.35 kilograms. A 70 kg person is about 154.3 pounds, or 11 stone and 0.3 pounds. A tonne is 1,000 kilograms. The converter handles the factors so you can read weights from different countries.

Luggage, shipping and fitness

Airlines often limit checked bags to 23 kilograms, which is about 50.7 pounds, so a scale that shows pounds needs converting. Couriers charge by weight, sometimes by volumetric weight, so check the rules. Fitness weights come in kilograms or pounds, and a 20 kg barbell is about 44 lb, which is why plates in a gym may not add up neatly. Weigh in the units your scale uses and convert for the destination.

Troy ounces and precious metals

Gold, silver and platinum are measured in troy ounces, which are about 31.1035 grams and heavier than the ordinary ounce of 28.35 grams. A pound has 16 ordinary ounces but a troy pound has 12 troy ounces. Mixing them up leads to costly errors. For South Asian gold weights use the Tola to Gram Converter.

Mass versus weight

In everyday talk weight and mass mean the same, and the kilogram and pound are mass units. Strictly, weight is the force of gravity on a mass and changes with location, while mass does not. Ordinary scales are calibrated for Earth. For precise lab or trade measurements use calibrated instruments, and record both the unit and the instrument's accuracy.

Stones, pounds and shipping weight

In the United Kingdom, body weight is often given in stones and pounds. A weight of 11 stone 3 pounds is 157 pounds, or about 71.2 kg. Couriers may charge by volumetric weight as well as actual weight. A common formula is length times width times height in centimetres, divided by 5,000, so a box of 40 by 30 by 30 cm counts as 7.2 kg even if it weighs less. The higher of the two weights usually sets the price, so check the carrier's rule before you ship.

Fitness, babies and the kitchen

A few reference conversions are used constantly. A weight of 500 g is about 1.1 pounds, a 45 pound gym plate is about 20.4 kg, and 100 kg is about 220.5 pounds. A baby born at 3.5 kg weighs about 7 pounds 11 ounces. In recipes, 1 pound is 16 ounces or about 454 grams. When you track fitness progress, record weights in one unit and convert only when you share the numbers, so that rounding does not create false changes from week to week.

Worked examples

A weight of 82 kilograms is about 180.8 pounds. A weight of 150 pounds is about 68.04 kilograms. Twelve ounces is about 340 grams. A person who weighs 9 stone 6 pounds weighs 132 pounds, or about 59.9 kilograms, since a stone is 14 pounds. When you convert, keep a few extra decimals and round at the end. If the numbers will be used for something important, such as medication or shipping charges, double check the conversion with a second method or a second tool.

Scales and accuracy

Scales vary in accuracy. A bathroom scale may be off by half a kilogram or more, and readings change with the time of day, clothing and what you have eaten. Weigh yourself at the same time under the same conditions to track trends. Kitchen scales are more precise, often to the nearest gram, and are the best tool for baking. Postal and trade scales must be checked and sealed in many countries. Place a scale on a hard, flat surface and check that it reads zero before you use it.

Shipping and baggage

Weight conversions are common in travel and shipping. Airlines often allow checked bags of 20 to 32 kilograms, and a bag of 23 kilograms is about 50.7 pounds. Couriers price parcels in weight bands, so a parcel of 2.3 kilograms may be charged in the 2.5 kilogram band. Some carriers use dimensional weight, based on the size of the box, and charge for whichever is greater. Weighing before you travel and keeping a margin of a kilogram or two avoids fees at the airport.

Weight in health and cooking

Doses of some medicines depend on body weight, in milligrams per kilogram. Do not convert weights yourself for children's medicine; follow the label or ask a pharmacist or doctor. In cooking, grams are the clearest unit, and recipes that use pounds and ounces convert easily with the converter. Baby formula and pet food also use weight guidance. Where precision matters for health, use the unit stated by the professional or the product and confirm any conversion with them.

Key terms explained

A kilogram is the SI unit of mass and a gram is a thousandth of it. A tonne is a thousand kilograms. The pound and ounce are used in the United States and the United Kingdom, with sixteen ounces in a pound. A stone is fourteen pounds. A troy ounce measures precious metals. Mass is the amount of matter and weight is the force of gravity on it. Net weight excludes packaging, and gross weight includes it.

Rules of thumb and quick checks

A kilogram is about 2.2 pounds, so multiply kilograms by 2.2 for a quick estimate in pounds and divide pounds by 2.2 for kilograms. A pound is about 454 grams and an ounce about 28.35 grams. A stone is about 6.35 kilograms. For parcels, compare actual weight with volumetric weight, the box volume in cubic centimetres divided by 5,000. Weigh on a flat surface and check that the scale reads zero first.

Quick reference and sanity checks

Useful anchors make errors easy to spot. One kilogram is about 2.2 pounds, one pound is exactly 16 ounces, one stone is 14 pounds and one tonne is 1,000 kilograms. A US ton, also called a short ton, is 2,000 pounds, while a long ton is 2,240 pounds, so check which one a supplier means. If you convert from kilograms to pounds and the number gets smaller, something is wrong. Round only at the end, keep a few extra decimals while you chain conversions and remember that scales for food, parcels and jewellery have their own resolution, so a result with six decimals does not mean your scale is that accurate.

Frequently asked questions