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Convert weight and mass between kilograms, grams, milligrams, metric tons, pounds, ounces, stones, and long/short tons.

How It Works

How Weight Converter Works

Each supported unit has a fixed conversion factor to kilograms (the metric base unit) — for example, 1 pound = 0.453592 kg and 1 stone = 6.35029 kg. Your entered value is first multiplied by its "from" unit's factor to find the equivalent weight in kilograms.

That kilogram value is then divided by the "to" unit's factor to produce the final converted result, allowing conversion between any two of the supported units — metric or imperial — without a separate formula for each possible pairing.

Worked Example

See It In Action

150 lb converts to 68.04 kg (150 × 0.453592), which is also equal to about 10.71 stone or 68,038.8 grams.
Real-World Use Cases

Who Uses Weight Converter and Why

  • Converting a body weight reading between kilograms and pounds when following fitness or medical guidance from a source using the other unit.
  • Working out a shipping package's weight in kilograms from a pounds-and-ounces figure, or the reverse, for an international courier form.
  • Converting a recipe or industrial ingredient quantity given in grams into ounces or pounds.
  • Checking a UK body-weight figure given in stone against the kilograms or pounds you're more familiar with.
Common Mistakes

Mistakes to Avoid

  • Confusing a long ton, short ton, and metric ton — all three are called "tons" but represent different quantities (long ton ~1,016 kg, short ton ~907 kg, metric ton = 1,000 kg exactly), so picking the wrong one for a shipping or industrial figure introduces real error.
  • Treating "weight" and "mass" as if this tool measures a gravity-dependent force — in everyday usage the two terms are interchangeable, and that's what this converter handles (units of mass like kg and lb), not weight in the strict physics sense.
  • Forgetting that a stone equals 14 pounds when eyeballing a UK body-weight conversion — mentally approximating instead of using the actual ratio can throw the result off by several pounds.
Pro Tips

Tips for Best Results

  • If you're converting a UK-context weight (like a person's body weight described in stone), remember it's still commonly used there for that specific purpose even though most other measurements in the UK are metric.
  • For shipping or freight documents, double-check which ton definition the paperwork is using before selecting long ton, short ton, or metric ton — they're not interchangeable.
Troubleshooting

Fixing Common Problems

My converted ton figure looks off compared to what I expected. — Check which specific ton unit you selected — long ton, short ton, and metric ton all convert to noticeably different kilogram values, so using the wrong one is the most common cause of an unexpected result.

Glossary

Terms Explained

Stone: A unit of mass equal to 14 pounds, still commonly used for body weight in the UK and Ireland.

Long ton / short ton / metric ton: Three differently-defined "ton" units — roughly 1,016 kg, 907 kg, and exactly 1,000 kg respectively — that are easy to mix up despite the shared name.

FAQ

Frequently Asked Questions

What is the difference between a long ton and a short ton?
A short ton (used mainly in the US) is 2,000 lb (about 907.2 kg), while a long ton (used in the UK) is 2,240 lb (about 1,016 kg) — a metric ton, at 1,000 kg, falls between the two and is used in most of the rest of the world.
Is weight the same thing as mass?
In everyday conversions like this, weight and mass are used interchangeably, though technically mass (kg) is a measure of matter while weight is the force of gravity acting on that mass. For everyday and commercial use, this distinction rarely matters.
How many pounds are in a stone?
One stone equals 14 pounds — it's a traditional British and Irish unit still commonly used there for reporting body weight.