Weight Converter
Convert weight and mass between kilograms, pounds, ounces, stone, and more.
About the Weight Converter
This converter treats kilograms as the common anchor: whatever unit you enter is first converted to kilograms using its fixed international conversion factor, then that kilogram value is converted out to every other supported unit — grams, milligrams, pounds, ounces, stone, metric tons, and carats. Routing everything through one base unit means the conversion factors stay simple and consistent rather than needing a distinct formula for every possible pair (like ounces directly to stone).
To use it: enter a value, pick its starting unit, and every other unit updates instantly. For example, entering 1 stone (a unit still common for body weight in the UK) shows about 6.35 kg, 14 lb exactly, 224 oz, and roughly 6,350,293 mg. Use the precision selector to show more decimal places when converting into a much larger unit (like milligrams into metric tons, where the result is a tiny fraction) or fewer when you just need a rounded, at-a-glance figure.
How accurate are these conversions?+−
Every unit converts through kilograms as a base anchor using standard international conversion factors, so results are accurate to floating-point precision.
How many pounds are in a stone?+−
One stone equals exactly 14 pounds — a British and Irish unit still commonly used for reporting body weight in the UK, even though most other measurements there use metric.
Is a metric ton the same as a US "short ton"?+−
No — this converter uses the metric ton (1,000 kg, also called a tonne). A US short ton is about 907.18 kg and a UK long ton is about 1,016.05 kg, both different from the metric ton offered here.
Why does the precision selector matter for tiny or huge values?+−
Converting a small unit like milligrams into a large one like metric tons produces a very small decimal — raising the precision reveals that value instead of showing it rounded to 0. Lower precision is useful when you just need a quick approximate reading.
What is a carat used for, and how does it compare to a gram?+−
The carat is the standard unit for gemstone weight, defined as exactly 200 milligrams (0.2 grams) — so 5 carats equals exactly 1 gram.
Does this distinguish between mass and weight?+−
This tool converts mass units (kilograms, pounds, etc.), which stay constant everywhere. It doesn't compute weight-as-force (which depends on local gravity, e.g. on the Moon) — for everyday and scientific purposes, mass in these units is what "weight converter" tools are typically used for.