weight conversion calculator
A beautiful, ultra-simple, and fast tool for converting mass units. Type in any field to see all others update instantly.
What is a Weight Converter?
A weight (mass) converter is a fast online calculator that converts grams, kilograms, pounds, ounces, stones, tonnes and more—instantly. Our tool uses SI-exact constants (e.g., 1 lb = 0.45359237 kg, 1 oz = 28.349523125 g) so your results are accurate for cooking, fitness, shipping, science experiments, and everyday measurements.
Why users love it
- Lightning-fast, bi-directional conversion (type into any unit).
- Precision up to 8 significant digits with smart rounding.
- Shareable links (prefilled values) & copy-to-clipboard for quick use.
How to Use the Weight Conversion Calculator for Weight Converter?
- Enter a value in the unit you know (e.g., 2.5 kg or 12 oz).
- The tool auto-updates all other fields (g, kg, lb, oz, st, t…).
- Copy any result or share the page URL with your value embedded.
- Need exactness? Turn on high-precision mode to view full decimals.
- For big or tiny numbers, use scientific notation: 1e6, 2.3e-4.
Weight Conversion Chart | Quick Reference Table
| Unit (Name) | Abbrev | 1 unit = grams | 1 gram = units | To grams × | From grams × |
|---|---|---|---|---|---|
| Microgram | µg | 0.000001 | 1,000,000 | 0.000001 | 1,000,000 |
| Milligram | mg | 0.001 | 1,000 | 0.001 | 1,000 |
| Gram | g | 1 | 1 | 1 | 1 |
| Kilogram | kg | 1,000 | 0.001 | 1,000 | 0.001 |
| Ounce (Avoirdupois) | oz | 28.349523125 | 0.03527396195 | 28.349523125 | 0.03527396195 |
| Pound | lb | 453.59237 | 0.00220462262185 | 453.59237 | 0.00220462262185 |
| Stone | st | 6,350.29318 | 0.000157473044418 | 6,350.29318 | 0.000157473044418 |
| Short Ton (US) | ST | 907,184.74 | 0.0000011023113109 | 907,184.74 | 0.0000011023113109 |
| Long Ton (UK) | LT | 1,016,046.9088 | 0.0000009842065276 | 1,016,046.9088 | 0.0000009842065276 |
| Tonne (Metric) | t or MT | 1,000,000 | 0.000001 | 1,000,000 | 0.000001 |
Weight Conversion Formulas
General method (via grams as base):
grams = value × (gramsPerUnit[unit])resultInTarget = grams × (unitsPerGram[target])
Practical formulas
kg → g:
g = kg × 1000g → kg:
kg = g ÷ 1000lb → kg:
kg = lb × 0.45359237 ÷ 1000 = lb × 0.45359237➜ actuallykg = lb × 0.45359237kg → lb:
lb = kg ÷ 0.45359237oz → g:
g = oz × 28.349523125g → oz:
oz = g × 0.03527396195st → kg:
kg = st × 6.35029318US ton → kg:
kg = ST × 907.18474UK long ton → kg:
kg = LT × 1016.0469088t (metric) → kg:
kg = t × 1000
Worked examples
2.5 kg → lb=2.5 × 2.20462262185 ≈ 5.5116 lb12 oz → g=12 × 28.349523125 = 340.1942775 g75 lb → kg=75 × 0.45359237 = 34.01942775 kg