This calculator can convert values between the common weight and mass units.
Modify the values and click the calculate button to use
| Milky Way Galaxy | 1.15357 × 10⁴² kgor 5.8 × 10¹¹ solar mass |
| Sun | 1.9891 × 10³⁰ kg |
| Earth | 5.9736 × 10²⁴ kg |
| Moon | 7.3477 × 10²² kg |
| Atomic Mass Unit (u) | 1.660538782(83) × 10⁻²⁷ kg |
| Neutron | 1.67492729(28) × 10⁻²⁷ kgor 1.0086649156(6) u |
| Proton | 1.672621637(83) × 10⁻²⁷ kgor 1.00727646677(10) u |
| Electron | 9.10938215(45) × 10⁻³¹ kgor 5.4857990943(23)×10⁻⁴ u |
Our weight converter lets you switch between these units instantly:
Kilograms (kg)
Pounds (lbs)
Ounces (oz)
Grams (g)
Stones (st)
Tons (metric & imperial)
1 kilogram = 2.20462 pounds
That's the magic number. Everything else builds from here.
kg → lbs: Multiply by 2.20462
Example: 5 kg × 2.20462 = 11.0231 lbs
lbs → kg: Divide by 2.20462
Example: 10 lbs ÷ 2.20462 = 4.5359 kg
kg → lbs: Double + 10%
5 kg → 10 + 1 = 11 lbs (actual: 11.02)
lbs → kg: Half − 10%
10 lbs → 5 − 0.5 = 4.5 kg (actual: 4.54)
The base unit of mass in the metric system. Used by almost every country. Fun fact: since 2019, it's defined by Planck's constant, not a physical object.
Comes from the Roman "libra pondo" — that's why the symbol is "lbs." One pound = 16 ounces ≈ 0.4536 kilograms.
1/16 of a pound. But there are two kinds! Avoirdupois ounce (~28.35g) for everyday use. Troy ounce (~31.1g) for precious metals like gold. Don't mix them up!
Mostly used in UK and Ireland for body weight. One stone = 14 pounds. So "12 stone" = 168 pounds.
1/1000 of a kilogram. The go-to unit for cooking, science, and anything precise.
The most common reason people convert weight. A recipe in grams but your cups are in ounces? For baking, weight is way more accurate — 100g of flour is always 100g, but a cup can vary. 200g ≈ 7 ounces.
Tracking weight loss or muscle gain with a pound scale but a kg app? Or following a workout program from another country. Our converter makes switching effortless.
Shipping costs are weight-based. UPS uses pounds, international uses kilograms. Know the exact weight so you don't overpay or underpay.
Physics and chemistry problems mix metric and imperial. Our calculator helps check your work. Just show your steps — teachers want to see the process.
Mistake #1: Confusing Weight and Mass
Weight = gravity's force on an object. Mass = how much stuff. On Earth they're similar. On the moon, you'd weigh less but mass stays the same. Our calculator assumes Earth.
Mistake #2: Forgetting to Round
Exact conversion is 2.20462. Rounding to 2.2 is fine for most things. But for precise work like chemicals or shipping costs, use the exact number.
Mistake #3: Mixing Up Ounces
Troy ounces (31.1g) are for gold and silver. Avoirdupois ounces (28.35g) are for cooking. Mixing them up costs money or ruins recipes.
Mistake #4: Using the Wrong Conversion Factor
Multiply by 2.2 for kg→lbs, divide by 2.2 for lbs→kg. Always double-check which direction you're going.
Type the number you want to convert in the "From" box.
Select the unit you're starting with (like pounds).
Select the unit you want to convert to (like kilograms).
The answer appears instantly in the "To" box. Click swap to flip the conversion.
That's it. No buttons to click. No waiting. Just instant results.
Use It for Batch Conversions: If you have a list of weights to convert, do them one at a time. Fast enough for 20 conversions in under a minute.
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Use It on Mobile: Responsive interface looks great on any screen size.
Accuracy
We use exact conversion factors, not rounded ones.
Speed
Results appear instantly as you type.
Free
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No limits
Use it as many times as you want.
We built this calculator because we needed it ourselves. And we wanted to share it with everyone.
Thousands of years ago, people used whatever was handy to measure weight — grains of wheat, stones, the weight of a person's foot. Obviously, that wasn't very consistent. So different cultures developed their own systems.
The Romans had the "libra," which became the pound. The British added the stone and the ounce. And the French invented the metric system during the French Revolution.
Today, most of the world uses metric. But the US, Liberia, and Myanmar still use imperial. That's why we need weight converters in the first place.
Mass is how much stuff something is made of. It doesn't change no matter where you are. Weight is the force of gravity pulling on that mass. It changes depending on gravity.
On Earth, your weight and mass are basically the same number (with the right units). But on Mars, you'd weigh less because gravity is weaker. Our calculator assumes you're on Earth — so don't use it for space travel!
Double the number, then add 10%. For example, 5 kg becomes 10, plus 1, equals 11 lbs. It's not exact, but it's close enough for everyday use.
A metric ton (or tonne) is 1,000 kilograms. An imperial ton is 2,000 pounds, which is about 907 kilograms. So a metric ton is heavier by about 93 kilograms.
The stone is a traditional British unit. One stone equals 14 pounds. It's still used in the UK and Ireland for measuring body weight, but most other countries use kilograms.
There are 28.35 grams in an avoirdupois ounce (the kind used for cooking and everyday things). But there are 31.1 grams in a troy ounce (used for precious metals).
Absolutely! It's perfect for converting recipe measurements. Just make sure you're using the right units. Most recipes use grams or ounces.
The biggest mistake is mixing up the direction. People multiply by 2.2 when they should divide, or vice versa. Always double-check which way you're going.
Divide the number of pounds by 14. For example, 168 pounds divided by 14 equals 12 stone. Our calculator does this instantly.
Yes, it uses exact conversion factors. But for very precise scientific work, you might need more decimal places. Our calculator gives you enough accuracy for most purposes.
It comes from the Latin word "libra," which means scales or balance. The ancient Romans used "libra pondo" meaning "a pound by weight." The "lbs" abbreviation stuck around for over 2,000 years.