Weight Converter

Convert between mass & weight units instantly — pick any from and to unit.

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About the Weight Converter

The Weight Converter turns a figure in one unit of mass into its equivalent in another, covering the units people actually deal with day to day: kilograms, grams, metric tonnes, pounds, ounces, stones, and US/UK tons. Type a number, pick the unit you have and the unit you want, and you get the answer instantly. It exists because the world is split between two systems. The US uses pounds and ounces, the UK still weighs body weight in stones, and almost everywhere else runs on grams and kilograms, so a single number frequently has to be rewritten before it makes sense to the person reading it.

Reach for it whenever a weight in your head is in the wrong system for the task in front of you. Travelers check a 23 kg checked-bag limit against luggage that reads in pounds. Shoppers convert a recipe that lists 250 g of flour into ounces. Anyone tracking body weight switches between stones-and-pounds and kilograms, and shippers price freight by converting between kilograms and tonnes or US short tons. Rather than memorizing a dozen factors, you keep one tool open and let it handle every pairing, including the awkward ones like grams to ounces or stones to kilograms.

Under the hood the math is simple and exact: every unit is defined against a single base, then converted through it. One pound is defined as exactly 0.45359237 kilograms (set by the 1959 International Yard and Pound Agreement), so 1 kg equals about 2.20462 lb. From there the rest follow: 1 kg = 1000 g = 35.274 oz, 1 lb = 16 oz, 1 stone = 14 lb (about 6.35029 kg), and 1 metric tonne = 1000 kg. The converter applies these fixed factors, so results are repeatable and match official definitions rather than rough rules of thumb.

Two accuracy notes worth keeping in mind. First, this tool converts mass, not force: a 70 kg person has the same mass on the Moon, even though their bodyweight (the gravitational force) would feel about one-sixth as much. In everyday use that distinction rarely matters, but it explains why scientists separate the two. Second, the calculation runs entirely in your browser. Nothing you type is uploaded or stored on a server, so you can convert sensitive figures, like a shipment weight or a personal bodyweight log, knowing the numbers never leave your device.

Frequently asked questions

How many pounds are in a kilogram?

One kilogram equals about 2.20462 pounds. The exact basis is the reverse definition: one pound is exactly 0.45359237 kilograms, so dividing 1 by that figure gives the 2.20462 conversion factor.

How do I convert stones to kilograms?

Multiply the number of stones by 6.35029. One stone equals 14 pounds, and since each pound is 0.45359237 kg, one stone works out to roughly 6.35029 kg.

What is the difference between mass and weight in this converter?

The tool converts mass, the amount of matter, between units like kilograms and pounds. True weight is the gravitational force on that mass, but in everyday language the two are used interchangeably, so the conversions match what people expect on a scale.

How many grams are in an ounce?

One ounce equals approximately 28.35 grams. There are 16 ounces in a pound, and one pound is about 453.59 grams.

Is a US ton the same as a metric tonne?

No. A US short ton is 2,000 pounds (about 907 kg), a UK long ton is 2,240 pounds (about 1,016 kg), and a metric tonne is exactly 1,000 kg (about 2,204.62 pounds). The converter keeps them separate so you pick the right one.

From our blog

Sticks, Cups, or Grams? A Practical Guide to Measuring Butter

By the Super Simple Digital Tools Team · Updated June 2026

Few ingredients cause as much measuring confusion as butter. In the United States it comes in wrapped sticks and is scooped by the cup or tablespoon; in Britain and Europe it arrives as a solid block and is weighed in grams; and plenty of vintage recipes still list it in ounces. None of these systems is wrong, but they rarely agree at a glance, which is why a quick conversion saves a lot of squinting at wrappers and mental arithmetic.

The good news is that butter conversions are built on a short list of fixed relationships. A single US stick is one half cup, eight tablespoons, four ounces, and about 113 grams. From there everything follows: a cup is two sticks or roughly 227 grams, a half cup is one stick, and a full pound is four sticks or about 454 grams. Memorise the stick and you can rebuild every other figure, because the units simply scale up and down from that one reference point.

Where people get caught out is mixing weight with volume. Grams measure how heavy the butter is, while cups and tablespoons measure how much space it takes up. The conversion between them only holds because butter has a fairly consistent density of about 0.911 grams per millilitre. That is why a tablespoon lands at roughly 14 grams rather than a round number, and why melted or whipped butter, which traps air or flows differently, will not pack into a cup the same way a cold block does.

International swaps deserve special care. The most common slip is assuming a 250 gram European block equals two American sticks. Two sticks are only 227 grams, so the block holds about 23 grams more, a little over a tablespoon and a half. For everyday baking you can trim 225 grams off the block to replace two sticks and move on. European butter also tends to have a slightly higher fat content than US butter, which mostly affects richness rather than the measurement itself.

Once you understand the ratios, a converter just removes the friction. Enter what your packaging or recipe gives you, read off the unit you need, and portion the butter with a knife against the printed wrapper marks or a kitchen scale. For precision baking, weighing in grams is the most reliable method because it sidesteps how firmly butter is pressed into a cup. For quick cooking, the stick and tablespoon marks are fast and accurate enough that nobody will notice the difference.

  • Use the printed lines on a US butter wrapper to slice tablespoons and 1/8-cup portions without a scale.
  • When a recipe needs two sticks but you have a 250 g block, cut off 225 g and set the rest aside.
  • For baking that depends on exact ratios, weigh butter in grams rather than packing it into a cup.
  • Soften or melt butter only after measuring it cold, since warm butter changes how it fills a measuring cup.

Read the full guide →

Tool by the Super Simple Digital Tools Team. Reviewed by our editorial team. Free to use, no signup required.

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