Convert weight and mass between kilograms, grams, milligrams, metric tonnes, ounces, pounds, stone and US tons instantly — accurate metric-to-imperial conversions for cooking, shipping, travel, fitness and science.
Enter a weight value to convert between units
This free weight converter instantly changes a weight or mass value between milligrams, grams, kilograms, metric tonnes, ounces, pounds, stone, and US tons — all at once, in a single result table. Rather than looking up one conversion factor at a time, you enter a value once and immediately see it expressed in every supported unit, which makes this tool as useful as a general-purpose mass converter as it is a quick recipe or shipping weight check. Whether you call it a weight converter or a weight conversion calculator, the underlying math is the same standard, publicly documented set of conversion factors used below.
Enter a numeric value and choose its starting unit, and the calculator converts it into grams internally before recalculating that figure into milligrams, grams, kilograms, metric tonnes, ounces, pounds, stone, and US short tons. The result table highlights your original unit and lists every equivalent side by side, so you never have to run the same conversion twice to compare two or three units at once.
Cooks and bakers use it to translate recipes between grams and ounces. Travelers and expats use it to make sense of grocery labels and luggage limits written in an unfamiliar unit. Fitness users track bodyweight across kilograms, pounds, and UK stone. Shippers and logistics teams estimate freight charges in kilograms, metric tonnes, and US tons. Online shoppers double-check a product's shipping weight before checkout. Students and scientists convert lab measurements between grams and milligrams, and nurses or caregivers convert a patient's weight between kilograms and pounds for dosing and charting. Anyone who needs a fast, dependable weight or mass conversion falls into this tool's intended audience.
Different countries and industries settled on different weight units for historical reasons — the US still runs on pounds and ounces, the UK mixes stone and pounds for body weight, and most of the rest of the world uses the metric kilogram and gram. Shipping and freight documents can specify either metric tonnes or US short tons, which are close but not interchangeable. A reliable converter removes the guesswork and rounding errors that come from doing these conversions by hand, especially when the stakes involve a recipe, a medication dose, or a shipping invoice.
The exact conversion factors this weight converter uses for every supported unit
The kilogram is technically a unit of mass — the amount of matter in an object — while weight is the force gravity exerts on that mass. In everyday language, including on this calculator, the two terms are used interchangeably under standard Earth gravity.
Stone (14 lb) remains the everyday unit for reporting adult body weight in the UK and Ireland, almost always written as whole stone plus pounds, such as "11 stone 8," rather than as a decimal.
The kilogram is the International System of Units (SI) base unit for mass, as defined and maintained by the International Bureau of Weights and Measures (BIPM). Every metric unit here is derived from it.
From entering a value to reading the full conversion table
Type the weight or mass amount into the value field, for example 75 or 8.
Choose the unit your value is currently in, such as kilogram, pound, ounce, or stone, from the From Unit dropdown.
The calculator converts your value into grams internally, then recalculates it into every supported unit.
See your value instantly converted into milligrams, grams, kilograms, tonnes, ounces, pounds, stone, and US tons, with your starting unit highlighted.
Change the value or starting unit and click Convert again, or use Reset to return to the default 1 kg.
Two realistic conversions — a body weight reading and a cooking measurement
You have a body weight reading of 75 kg and want to know it in pounds and UK stone.
A recipe calls for 8 oz of an ingredient, but your kitchen scale only reads grams.
| Example | Input | kg | lb | oz | g | st |
|---|---|---|---|---|---|---|
| 1. Body weight | 75 kg | 75 | 165.3468 | 2,645.55 | 75,000 | 11.8105 |
| 2. Recipe ingredient | 8 oz | 0.226796 | 0.5 | 8 | 226.796 | 0.035714 |
Explanation: Both examples follow the same two-step logic: multiply the input by its unit's gram factor to get a base value in grams, then divide that base value by the target unit's gram factor. Because every unit shares the same gram base, the result table for one input can show all eight units at once without any extra lookups.
What the result table shows and how to read it in context
| Column | What It Means | Typical Use |
|---|---|---|
| Unit | Every supported weight/mass unit, from milligrams up to US tons. | Scan for the unit you actually need |
| Value | Your entered amount, re-expressed in that unit using the standard conversion factors. | Compare figures across metric and imperial at a glance |
| Highlighted row | Marks the unit you originally entered, so you can quickly see your starting point among the results. | Confirm the conversion started from the right unit |
Country and industry context matter. A "165 lb" reading means little to someone who only thinks in kilograms, and a "75 kg" reading means little to someone who only thinks in stone or pounds — that's why the table shows every unit at once rather than a single converted number.
Shipping and freight documents should always specify metric tonne vs. US short ton, since the two differ by roughly 10%; this converter clearly separates them into their own rows.
Small quantities (cooking, lab work, jewelry) are usually easier to compare in grams, milligrams, or ounces, while large quantities (freight, agriculture, industrial materials) are easier to compare in kilograms, metric tonnes, or US tons.
Where fast, reliable weight and mass conversion is genuinely useful
Convert recipe ingredients between grams and ounces when following a recipe written for a different kitchen scale.
Check an airline's kilogram baggage allowance against a bag weighed in pounds before you fly.
Track bodyweight progress across kilograms, pounds, and UK stone in one consistent log.
Estimate freight cost or customs declarations using kilograms, metric tonnes, or US tons.
Convert a patient's weight between kilograms and pounds for charting or dosage calculations.
Check unit conversion homework in physics, chemistry, or general science classes.
Convert sample mass between grams and milligrams for lab notebooks and reports.
Check a product's shipping weight or net weight when it's listed in an unfamiliar unit.
Convert crop yield or feed weight between kilograms, tonnes, and US tons for record-keeping.
Convert small item weights between grams and ounces when comparing listings from different regions.
Log a pet's weight consistently in kilograms or pounds between vet visits.
Convert material weight between kilograms and US tons when working across metric and imperial spec sheets.
Convert a newborn's weight between kilograms/grams and pounds/ounces for family and medical records.
Check a parcel's weight against postal service limits listed in grams or ounces.
What this weight converter does well, and where it has boundaries
Frequently used weight and mass conversions, calculated from this calculator's exact factors
| Conversion | Equivalent |
|---|---|
| 1 kg | 2.20462 lb |
| 1 kg | 35.274 oz |
| 1 kg | 0.157473 stone |
| 1 kg | 1,000 g |
| 1 lb | 453.592 g (0.453592 kg) |
| 1 lb | 16 oz |
| 1 stone | 14 lb (6.35029 kg) |
| 1 oz | 28.3495 g |
| 1 metric tonne (t) | 1,000 kg (2,204.62 lb) |
| 1 US ton (short) | 2,000 lb (907.18474 kg) |
| 1 g | 1,000 mg |
| 1 kg | 1,000,000 mg |
Summary: This weight converter turns any single kilogram, gram, milligram, tonne, ounce, pound, stone, or US-ton value into a full side-by-side table across all eight units, using standard conversion factors traceable to the SI and NIST. It's a fast, free way to handle recipes, luggage limits, bodyweight tracking, shipping, and lab conversions without manual math. Pair it with the Unit Converter and Cooking Measurement Converter for other everyday conversions.
Common questions about weight and mass conversion
Trusted standards bodies that define and maintain weight and mass units
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