Weight Converter
Convert between kilograms, pounds, ounces, grams, stones, carats, and more weight/mass units — plus a gold & precious metal purity calculator (karat, fineness).
Everyday Uses
Luggage allowances
Airline limit says 23 kg, your bathroom scale reads 47 lb — convert to know if you're packing a problem before the check-in counter does.
International recipes
A British recipe wants 450 g of flour, your kitchen scale shows ounces. Convert precisely — baking is chemistry and rough guesses show.
Gym plates abroad
Traveling and the gym plates are in kilos? Convert your usual working weight so you don't under- or over-load the bar.
Shipping costs
Carriers quote by kg or lb depending on the service — convert your parcel's weight to compare rates fairly.
Frequently Asked Questions
How many pounds are in a kilogram, and how do you convert between them?
1 kg = 2.20462 lbs. To convert kg to pounds, multiply by 2.205. To convert pounds to kg, multiply by 0.4536 (or divide by 2.205). Quick mental math: double the kg value and add 10% — e.g. 70 kg → 140 + 14 = 154 lbs. Common reference: 1 kg ≈ 2.2 lbs; 100 kg = 220.5 lbs; a 16 lb bowling ball weighs about 7.26 kg.
What is a carat, and how is it different from karat?
Carat (ct) is a unit of mass for gemstones and pearls: 1 carat = 0.2 grams = 200 milligrams exactly, standardised internationally since 1907. Karat (kt) is a completely different concept — it measures gold purity on a 24-point scale, not weight. A "2-carat diamond" describes its mass; an "18-karat ring" describes the gold's purity (75% pure gold). The similar spelling causes frequent confusion, but one is a weight unit and the other is a purity scale.
What is the difference between weight and mass, and does it matter for conversions?
Mass is the amount of matter in an object (kilograms, grams) — it never changes. Weight is the force of gravity on that mass (newtons) — it changes on the Moon or in space. In everyday use "weight" and "mass" are used interchangeably, and kg/lbs conversions treat them the same way. Technically, a 70 kg person weighs 686 newtons on Earth but only 114 N on the Moon (1/6th gravity) — though their mass stays 70 kg.
What is gold karat and fineness, and how do they relate to purity percentage?
Karat (kt) measures gold purity on a 24-point scale where 24kt = 100% pure gold. Fineness expresses the same purity per mille (parts per 1,000) — e.g. 18kt = 750 fineness = 75% pure gold. Common marks: 24kt/999 (fine gold), 22kt/916, 18kt/750, 14kt/585, 10kt/417, 9kt/375. To convert: fineness = karat ÷ 24 × 1000; karat = fineness ÷ 1000 × 24. Sterling silver is marked 925 fineness (92.5% silver); fine silver is 999.
How many ounces are in a pound, and how does the stone unit work?
1 pound = 16 ounces (avoirdupois, the everyday system). 1 stone = 14 pounds = 6.35 kg. The stone is commonly used for body weight in the UK and Ireland. Note: the troy ounce (used for precious metals like gold and silver) ≠ avoirdupois ounce: 1 troy oz = 31.1035 g vs 1 av. oz = 28.3495 g — a 1 oz gold bar is a troy ounce, not a regular ounce, so it weighs about 10% more than you might expect.
How do you convert kilograms to stones and pounds?
Step 1: divide kg by 6.35029 to get stones (with decimal). Step 2: the integer part is stones; multiply the decimal part by 14 to get remaining pounds. Example: 75 kg ÷ 6.35029 = 11.81 stone → 11 stone + (0.81 × 14) = 11 stone 11.3 lbs ≈ 11 st 11 lb. Reverse: (stones × 14 + pounds) × 0.4536 = kg.
What are common weight conversion benchmarks to memorise?
Useful reference weights: 1 oz = 28.35 g. 1 lb = 453.6 g. 1 kg = 2.205 lbs. 1 carat = 0.2 g (a 1-carat diamond fits on a fingertip). 1 troy oz = 31.1 g (a standard gold coin). 1 stone = 6.35 kg. 1 US ton (short ton) = 2,000 lbs = 907.2 kg. 1 metric tonne = 1,000 kg = 2,205 lbs. A standard bag of sugar = 1 kg; a US nickel coin = 5 g; a paperclip ≈ 1 g.