Free Weight Converter
Convert between pounds, kilograms, ounces, grams, stones, and tons. Instant weight and mass unit conversion calculator.
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1 Pounds =
Formula
Converted Value = Input Value × (Source Unit in grams) ÷ (Target Unit in grams)How to Convert Weight and Mass Units
This weight converter translates between all common imperial and metric mass units. Every conversion normalizes to grams first, then converts to your desired unit. This ensures accuracy across all unit combinations.
Imperial Weight Units
- Ounces (oz) — used for food, mail, and small items. 16 ounces = 1 pound. A slice of bread weighs about 1 oz.
- Pounds (lbs) — the standard weight unit in the US. 1 pound = 453.592 grams.
- Stones (st) — used in the UK for body weight. 1 stone = 14 pounds.
- US Tons (short tons) — used for heavy loads in the US. 1 US ton = 2,000 pounds.
Metric Weight Units
- Milligrams (mg) — used for medications and vitamins. 1,000 mg = 1 gram.
- Grams (g) — the base metric unit. A paperclip weighs about 1 gram.
- Kilograms (kg) — used worldwide for body weight, groceries, and shipping. 1 kg = 2.205 lbs.
- Metric Tons (tonnes) — used for vehicles, cargo, and industrial weights. 1 tonne = 1,000 kg.
Common Weight References
- Smartphone: 6-7 oz (170-200 g)
- Basketball: 1.4 lbs (624 g)
- Gallon of water: 8.34 lbs (3.78 kg)
- Average car: 1.5 US tons (1,361 kg)
Whether you're calculating shipping costs, converting a recipe, checking luggage weight for a flight, or tracking body weight in a different unit system, this converter gives you instant, accurate results for any weight unit.
Frequently Asked Questions
How do I convert pounds to kilograms?
Divide pounds by 2.205 (or multiply by 0.4536) to get kilograms. For example, 150 lbs ÷ 2.205 = 68.04 kg. A quick mental shortcut: divide by 2 and subtract 10% — 150 ÷ 2 = 75, minus 7.5 = 67.5 kg (close to actual 68 kg).
How many grams are in an ounce?
There are 28.3495 grams in one ounce (avoirdupois). For precious metals, a troy ounce is slightly heavier at 31.1035 grams. A standard letter weighs about 1 ounce (28 grams).
What is a stone in weight?
A stone is a unit of weight equal to 14 pounds (6.35 kg). It's commonly used in the UK and Ireland for measuring body weight. For example, 170 lbs = 12 stone 2 lbs.
What is the difference between a US ton and a metric ton?
A US ton (short ton) is 2,000 pounds (907.185 kg). A metric ton (tonne) is 1,000 kilograms (2,204.6 pounds). The metric ton is about 10% heavier. There's also the Imperial ton (long ton) at 2,240 pounds, used in the UK.
How do I convert my weight for international travel?
Most countries use kilograms. Divide your weight in pounds by 2.205. Common conversions: 120 lbs = 54.4 kg, 150 lbs = 68 kg, 180 lbs = 81.6 kg, 200 lbs = 90.7 kg. Airlines also list luggage limits in kilograms (usually 23 kg for checked bags).