Converter Tools

Weight Converter

Convert weight between milligrams, grams, kilograms, metric tons, ounces, pounds and stone. A simple everyday weight converter using precise mass-unit factors. Fully offline.

Runs entirely in your browser — nothing you type is uploaded.

This tool runs in your browser. Please enable JavaScript to use it — the guide below explains what it does.

Note: the converter runs in your browser with JavaScript. With JavaScript off you can read this guide, but the controls will not appear.

Convert weight quickly and accurately

This everyday weight converter changes a value between common units entirely in your browser. Enter an amount, choose the units, and get a precise result. (Technically these are units of mass, but they're what people use to talk about weight day to day.)

How it works

  1. Enter an amount (decimals and zero are allowed).
  2. Choose the From and To units.
  3. Click Convert, or Swap to reverse the direction.
  4. Copy the result or Reset to start again.

Supported units & reference factors

  • Metric — milligram, gram, kilogram (base), metric ton (1000 kg).
  • Imperial / US — ounce (0.028349523125 kg), pound (0.45359237 kg), stone (6.35029318 kg).
  • Base unit — every value is converted through kilograms for accuracy.

Examples

  • 1 kilogram = 1000 grams ≈ 2.204623 pounds
  • 16 ounces = 1 pound
  • 1 stone = 6.350293 kilograms

Weight vs mass

Strictly speaking, kilograms, pounds and ounces measure mass, while weight is a force. In everyday use the terms are interchangeable, and this tool performs accurate mass-unit conversions — which is exactly what you want when converting a recipe, a parcel or a body weight.

Privacy

Everything runs locally in your browser. The values you enter are never uploaded, stored or shared, and the tool makes no network requests.

Frequently Asked Questions

Which weight units are supported?
Milligram, gram, kilogram, metric ton, ounce, pound and stone — convert from any to any other.
Is this weight or mass?
In everyday use people say “weight”, and that is how this tool is meant to be used. Technically these are units of mass, and the conversions are precise mass-unit conversions — for example 1 pound = 0.45359237 kg and 1 ounce = 0.028349523125 kg.
How accurate is it?
It converts through kilograms using exact defined factors, so results such as 16 ounces = 1 pound and 1 kg ≈ 2.20462 lb are precise, formatted cleanly without floating-point noise.
Can I use decimals, zero or negative values?
Yes. Decimals and zero are supported, and negative values are converted mathematically. Non-numeric, NaN or infinite input is rejected with a clear message.
Is my data stored or sent anywhere?
No. All conversions run locally in your browser — the values you enter are never uploaded, saved or shared, and the tool makes no network requests.

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