Weight Conversion
Mass conversion units
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Quick Answer
1 kg = 2.205 lbs. 1 lb = 453.6 g. 1 oz = 28.35 g. 1 metric tonne = 1000 kg = 2204.6 lbs. Mass is constant everywhere; weight depends on gravity.
Weight and Mass Conversion Calculator
Convert between mass units: kilograms, grams, milligrams, pounds, ounces, and grains.
Key Conversions
- 1 kg = 2.205 lb = 35.274 oz
- 1 lb = 453.6 g = 16 oz
- 1 oz = 28.35 g
Design Notes
Component weight matters for shipping cost calculations, vibration analysis, and aerospace applications. A loaded PCB typically weighs 50-500g. BOM weight estimation helps predict shipping costs early in product design.
Common Mistakes
- 1
Confusing avoirdupois ounces (28.35g, everyday use) with troy ounces (31.1g, precious metals).
- 2
Mixing up metric tonnes (1000 kg) with US short tons (907 kg) or Imperial long tons (1016 kg).
- 3
Using 'weight' when 'mass' is meant — they are different physical quantities (weight = mass × gravity).
Knowledge Base
How many grams in an ounce?
1 avoirdupois ounce = 28.3495 grams. 1 troy ounce (used for precious metals) = 31.1035 grams. An ounce of gold (troy) is actually heavier than an ounce of feathers (avoirdupois). Quick conversion: 1 oz ≈ 28 g.
How many pounds in a kilogram?
1 kg = 2.20462 pounds. 1 pound = 0.453592 kg exactly (since 1959). Quick mental math: divide kg by 2 and add 10% for a rough estimate. Example: 80 kg ≈ 80/2 + 8 = 48 + 8 = 176 lbs (actual: 176.4 lbs).
What is the difference between mass and weight?
Mass (kg, g) measures the amount of matter and is constant everywhere. Weight (N, lbf) is the gravitational force on mass: W = m × g. In everyday use, 'weight' typically refers to mass. A 70 kg person weighs 686 N on Earth but only 114 N on the Moon, while their mass remains 70 kg.
What is a metric ton?
1 metric tonne = 1000 kg = 2204.6 lbs. 1 US (short) ton = 2000 lbs = 907.2 kg. 1 Imperial (long) ton = 2240 lbs = 1016 kg. The metric tonne is 10% larger than a US ton. International shipping uses metric tonnes. US construction uses short tons.
What is a grain?
1 grain = 0.0648 grams = 64.8 mg. Used for bullet weights (55-230 grain), gunpowder charges, and pharmaceutical dosages. 1 pound = 7000 grains. 1 troy ounce = 480 grains. The grain is the same in avoirdupois, troy, and apothecary weight systems.
What is a stone?
1 stone = 14 pounds = 6.35 kg. Used in the UK and Ireland for body weight. A 150 lb person = 10 stone 10 lbs. One of the few Imperial units with no metric equivalent that is still in common daily use.
How do I weigh electronic components?
SMD resistors and capacitors weigh milligrams: 0402 ≈ 1 mg, 0805 ≈ 10 mg, 1206 ≈ 20 mg. A loaded PCB typically weighs 50-500g depending on size. Component weight matters for: shipping costs, vibration resistance, and aerospace applications where every gram counts.
What is a carat?
1 carat = 200 mg = 0.2 grams. Used for gemstones. Not to be confused with karat (gold purity): 24 karat = pure gold, 18 karat = 75% gold. A 1-carat diamond weighs 0.2g and is about 6.5mm in diameter.
How do I convert ounces and pounds?
1 pound = 16 ounces. 1 ounce = 1/16 pound = 0.0625 pounds. To convert ounces to pounds: divide by 16. Example: 40 oz = 40/16 = 2.5 lbs. Note: fluid ounces (volume) and avoirdupois ounces (weight) are different units despite sharing the name.
What are troy ounces and where are they used?
1 troy ounce = 31.1035 g (vs 28.35 g for avoirdupois ounce). Used exclusively for precious metals (gold, silver, platinum). Gold prices are always quoted per troy ounce. 1 troy pound = 12 troy ounces = 373.2 g (lighter than an avoirdupois pound of 453.6 g). Confusingly, a troy ounce is heavier than a regular ounce.