glunty Weight converter (kg, lb, oz, g)
Type a value in mg, g, kg, tonnes, oz, lb, or stones. Every other unit updates live. Local only.
- Runs in your browser
- No sign-up
- No watermark
- No installs
What this tool does
Converts a weight (more precisely, a mass) between seven units: milligrams, grams, kilograms, metric tonnes, ounces, pounds, and stones. It is two-way and live, so typing a valid number in any field updates the other six instantly, with no button to press and no direction to choose. Grams are the internal base unit, and the tool uses the exact defined factors (1 ounce is 28.349523125 grams, 1 pound is 453.59237 grams, 1 stone is 14 pounds, 1 tonne is 1,000,000 grams). Everything runs in your browser with plain JavaScript arithmetic; nothing you type leaves your machine. Verify it yourself: open DevTools, open the Network tab, and watch it stay empty. Zero requests.
How to use it
Put your number in the field for the unit you already have. To convert kg to lbs, type into the Kilograms box and read the Pounds box. To convert grams to ounces, type into the Grams box and read the Ounces box. Results are shown to about eight significant figures with trailing zeros trimmed, so a round value like 16 shows cleanly rather than as a long decimal tail. Non-numeric input shows a short inline message and leaves the other fields untouched, and clearing a field empties the rest so no stale value lingers. A couple of quick sanity checks: 1 kg reads 1000 g and about 2.2046226 lb, 1 lb reads exactly 16 oz, and 1 stone reads exactly 14 lb. Press Clear to reset every field.
Common use cases
- Converting a recipe written in grams into ounces or pounds, or the other way.
- Reading a body weight quoted in stones and pounds as kilograms.
- Checking a shipping or postage weight across grams, ounces, and pounds.
- Turning a bulk figure in metric tonnes into kilograms or pounds.
- Converting small quantities in milligrams to grams for dosing or lab notes.
Common pitfalls
- This is mass, not force. The pound and ounce here are the avoirdupois units of mass, defined as fixed numbers of grams. That is different from pounds-force, a unit of force equal to the weight of one pound-mass under standard gravity. On Earth the everyday "weight" you read off a scale tracks mass closely, so the results match a kitchen or bathroom scale, but the mass-versus-force distinction is intentionally out of scope.
- A metric tonne is not a ton. The tonne here is exactly 1000 kilograms. The US short ton (2000 pounds) and the UK long ton (2240 pounds) are different units and are not offered. If your source says "ton," check which one it means before trusting a conversion.
- Ounces here are avoirdupois, not troy. One avoirdupois ounce is 28.349523125 grams and is used for food and postage. The troy ounce used for gold and silver is heavier (about 31.10 grams) and is a separate unit this tool does not cover.
- Displayed digits are rounded. Output is trimmed to about eight significant figures for readability, so treat the last shown digit as approximate. The conversion itself is computed at full precision first, then rounded only for display.
Frequently asked questions
- How do I convert kg to lbs (or lbs to kg)?
- Type your value into the Kilograms field and read the Pounds field. One kilogram is about 2.2046226 pounds, because a pound is defined as exactly 453.59237 grams. It works both ways: type a value into Pounds and the Kilograms field updates instantly. Every unit stays in sync as you type, so 70 kg shows as roughly 154.32 lb at the same time.
- How do I convert grams to ounces?
- Type into the Grams field and read the Ounces field. One ounce is exactly 28.349523125 grams (the international avoirdupois ounce), so 100 grams is about 3.5273962 ounces and 28.35 grams is close to one ounce. The reverse works too: type into Ounces to get grams. This is the ounce used for food and postage, not the troy ounce used for precious metals.
- How many ounces are in a pound, and how many pounds in a stone?
- There are exactly 16 ounces in one pound, and exactly 14 pounds in one stone. So one stone is 224 ounces, or about 6.3502932 kilograms. The stone is still common in the UK and Ireland for body weight. Type 1 into the Stones field to see all of these equivalents at once.
- What is a metric tonne, and is it the same as a ton?
- A metric tonne is exactly 1,000,000 grams, which is 1000 kilograms or about 2204.6226 pounds. It is not the same as the US short ton (2000 pounds) or the UK long ton (2240 pounds), which are different units and are out of scope here. This converter uses the metric tonne only, so a value of 1 in the Tonnes field always means 1000 kilograms.
- Does this convert weight or mass?
- It converts mass. Grams, kilograms, and tonnes are units of mass, and the avoirdupois pound and ounce are also defined as fixed masses. In everyday speech people say weight when they mean mass, and on the surface of the Earth the two track each other, so the results match what a kitchen or bathroom scale shows. The distinction between pounds as a unit of mass and pounds-force as a unit of force is a separate topic and is out of scope for this tool.
- How does the converter round its results?
- Values are shown to about eight significant figures with trailing zeros trimmed, which keeps both huge numbers (milligrams in a tonne) and tiny ones (tonnes in a gram) readable. The math itself uses the exact defined factors: 1 ounce is 28.349523125 grams, 1 pound is 453.59237 grams, 1 stone is 14 pounds, and 1 tonne is 1,000,000 grams. Only the on-screen display is rounded; the conversion is done at full precision first.
Cite this tool
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Citations use 2026 as the publication year. Access date is left as a fillable placeholder where the citation style expects one.