Weight Calculator
Convert weight and mass between kilograms, grams, pounds, ounces, stones, carats, grains and US, UK and metric tons. Edit any unit and the rest follow. Uses the exact definition 1 lb = 0.45359237 kg, so pounds, ounces, stones and tons convert without rounding drift.
What does the Weight Calculator do?
It converts a mass into 15 units: metric (µg, mg, g, kg, metric ton), the carat used for gemstones, and avoirdupois units (grain, dram, ounce, pound, stone, short and long hundredweight, short and long ton). Type in whichever unit you have and read the rest; nothing leaves your browser.
How to use
- Type a value in a row, e.g. 70 in Kilogram. The other rows show ≈ 154.324 lb and ≈ 11.0231 st.
- Set rounding digits for the number of decimals displayed.
- Turn on Description to see each unit's definition, Ratio to see how it relates to the top row, and Separators for thousands separators.
- Drag the handle at the left of a row to reorder units; the top row is the (base unit).
- Press Up / Down in a row to add or subtract 1 of that unit (for example, 1 lb at a time).
Units and definitions
| Unit | Symbol | Definition |
|---|---|---|
| Microgram / Milligram / Gram | µg / mg / g | 10⁻⁶ g / 0.001 g / 1 g |
| Kilogram | kg | 1,000 g (SI base unit) |
| Metric ton | t | 1,000 kg |
| Carat | ct | 0.2 g |
| Grain | gr | 1/7,000 lb = 64.79891 mg |
| Dram | dr | 1/16 oz |
| Ounce | oz | 1/16 lb = 28.349523125 g |
| Pound | lb | 0.45359237 kg (exact) |
| Stone | st | 14 lb |
| Short / long hundredweight | sh cwt / l cwt | 100 lb / 112 lb |
| Short ton (US) | tn sh | 2,000 lb = 907.18474 kg |
| Long ton (UK) | tn l | 2,240 lb = 1,016.0469088 kg |
Conversion examples
- 1 kg ≈ 2.20462 lb
- 1 lb = 16 oz = 453.59237 g
- 1 oz ≈ 28.3495 g
- 1 st = 14 lb ≈ 6.35029 kg
- 1 ct = 0.2 g = 200 mg
Features
- 15 mass units for cooking, body weight, shipping and jewelry
- Edit any row to convert in both directions
- Exact factors evaluated with 40-digit decimal arithmetic
- Rounding control, thousands separators, ratios and descriptions
- Unit order, value and options are remembered locally
FAQ
Are troy ounces supported?
No. The ounce here is the avoirdupois ounce (28.3495 g) used for food and everyday goods. The troy ounce used for precious metals (31.1035 g) is not included.
What is the difference between short ton, long ton and metric ton?
A short ton (US) is 2,000 lb, a long ton (UK) is 2,240 lb and a metric ton is 1,000 kg (≈ 2,204.62 lb).
Weight or mass?
Strictly, these units measure mass. In everyday use "weight" means the same thing, which is why the tool is called a weight calculator.