Weight Converter

Convert weight between any two units. Enter a value, choose From and To units — get the result instantly.

Enter your values above to see the results.

Tips & Notes

  • The stone (st) is used primarily in the UK and Ireland for body weight. 1 stone = 14 lbs = 6.350 kg. A person at 11 stone 4 pounds = (11 × 14) + 4 = 158 lbs = 71.67 kg.
  • Pharmaceutical weights use milligrams (mg). 1 mg = 0.001 g = 0.000001 kg. A typical painkiller tablet is 500 mg = 0.5 g.
  • All units convert through kilograms as the reference base. To convert ounces to stone: oz → kg → stone.
  • For cooking: 1 cup of water ≈ 236.6 g = 8.345 oz = 0.521 lbs. For postal: 1 oz limit = 28.35 g.
  • Metric prefixes for mass: mg = 10⁻³ g; g = base; kg = 10³ g; metric ton = 10⁶ g. Each step is ×1,000.

Common Mistakes

  • Confusing milligrams (mg) with micrograms (mcg/μg) in medication — 1 mg = 1,000 mcg. Mixing these up leads to 1,000× dosing errors.
  • Using imperial tons (short ton = 2,000 lbs) as metric tons — this converter uses metric tons (1 t = 1,000 kg = 2,204.6 lbs).
  • Expecting exact round numbers in cross-unit conversions — 1 pound equals 453.592 grams, not a round number.
  • Forgetting that stone + lbs must both be converted — 11 stone 6 lbs = (11 × 14) + 6 = 160 lbs = 72.57 kg.
  • Applying kg-to-lbs to liquids without checking density — 1 liter of water = 1 kg = 2.205 lbs, but other liquids differ.

Weight Converter Overview

The Weight Converter provides instant conversion between all seven major weight units. Select your source unit, target unit, and enter a value — get the result immediately.

Conversion factors (via kg as base):

1 kg = 2.20462 lbs = 1,000 g = 35.274 oz = 0.157473 stone = 1,000,000 mg = 0.001 metric tons
EX: 80 kg → lbs = 80 × 2.20462 = 176.4 lbs | stone = 80 × 0.157473 = 12.60 stone | oz = 80 × 35.274 = 2,821.9 oz
Complete weight conversion table:
Unit= kg= lbs= grams
1 kg12.204621,000
1 lb0.4535921453.592
1 gram0.0010.0022051
1 oz0.0283500.062528.3495
1 stone6.35029146,350.29
1 mg0.0000010.00000220.001
1 metric ton1,0002,204.621,000,000

Frequently Asked Questions

All weight units convert via kilograms. From kg: lbs = kg × 2.20462; g = kg × 1,000; oz = kg × 35.2740; stone = kg × 0.157473; mg = kg × 1,000,000; metric tons = kg / 1,000. Example: 75 kg = 165.35 lbs = 75,000 g = 11.811 stone.

The stone is a UK and Irish weight unit equal to exactly 14 pounds (6.35029 kg). Used almost exclusively for body weight. Common weights: 8 stone = 112 lbs; 10 stone = 140 lbs; 12 stone = 168 lbs.

Pharmaceutical weights use milligrams (mg) = 0.001 g for most drug dosages, and micrograms (mcg) = 0.001 mg for potent drugs. Common: acetaminophen 500 mg; ibuprofen 200 mg; aspirin 81 mg.

Total lbs = (stone × 14) + remaining lbs. Then kg = lbs × 0.453592. Example: 12 stone 8 lbs → (12 × 14) + 8 = 176 lbs → 176 × 0.453592 = 79.83 kg.

Metric ton = 1,000 kg = 2,204.6 lbs. Short ton (US) = 2,000 lbs = 907.18 kg. Long ton (UK) = 2,240 lbs = 1,016 kg. This converter uses metric tons.

All conversions use exact factors: 1 lb = 0.45359237 kg (exact by definition); 1 oz = 28.349523125 g; 1 stone = 6.35029318 kg; 1 metric ton = 1,000 kg exactly. Results are shown to 8 significant figures.