Weight Calculator Online Free Tool

    Weight Calculator

    Convert values between common weight and mass units with precision

    Weight Converter

    Modify the values and select units to convert
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    Common Weights Reference

    Notable masses from celestial bodies to everyday objects

    Astronomical Masses

    Andromeda Galaxy
    1.5 × 10⁴² kg
    ≈ 1.5 trillion solar masses
    Betelgeuse (Red Supergiant)
    3.5 × 10³¹ kg
    ≈ 18 solar masses
    Jupiter
    1.898 × 10²⁷ kg
    ≈ 318 Earth masses
    Mars
    6.4171 × 10²³ kg
    ≈ 0.107 Earth masses

    Particle Masses

    Carbon-12 Atom
    1.9926467 × 10⁻²⁶ kg
    = 12.000 u (by definition)
    Alpha Particle (Helium Nucleus)
    6.6446573 × 10⁻²⁷ kg
    ≈ 4.001506 u
    Muon (μ)
    1.883531 × 10⁻²⁸ kg
    ≈ 206.77 electron masses
    Tau Particle (τ)
    3.16754 × 10⁻²⁷ kg
    ≈ 3477 electron masses

    Everyday Objects Weight Comparison

    Common weights for reference

    Quick Conversion Tips

    Metric Conversions
    • 1 kg = 1,000 g = 1,000,000 mg
    • 1 metric ton = 1,000 kg
    • 1 g = 1,000 mg = 1,000,000 µg
    Imperial Conversions
    • 1 lb = 16 oz = 7,000 grains
    • 1 stone = 14 lb
    • 1 short ton (US) = 2,000 lb
    • 1 long ton (UK) = 2,240 lb
    Metric ↔ Imperial
    • 1 kg ≈ 2.205 lb
    • 1 lb ≈ 0.454 kg
    • 1 oz ≈ 28.35 g
    Everyday Reference
    • US nickel = 5 g
    • US penny = 2.5 g
    • 1 liter of water ≈ 1 kg

    The weight calculator converts between pounds, kilograms, ounces, grams, stones, and other weight/mass units. Whether you are converting body weight, measuring ingredients, shipping packages, or doing scientific calculations, enter your value and units to get an instant conversion.

    Weight Unit Conversions

    Unit= Pounds= Kilograms= Ounces
    1 pound (lb)10.45416
    1 kilogram (kg)2.205135.27
    1 ounce (oz)0.06250.02841
    1 gram (g)0.002200.0010.0353
    1 stone (UK)146.350224
    1 ton (US short)2,000907.232,000

    Common Weight References

    Having reference points helps quickly check if conversions make sense.

    ItemApproximate Weight
    US nickel5 grams
    Slice of bread28 grams (1 oz)
    Can of soda355 mL / 369 grams
    Smartphone170-200 grams
    Bag of flour (US)5 lbs (2.27 kg)
    Average adult (US)170 lbs (77 kg)

    Frequently Asked Questions

    How many pounds in a kilogram?

    There are 2.20462 pounds in one kilogram. The quick approximation: multiply kilograms by 2.2 to get pounds. Divide pounds by 2.2 to get kilograms. Example: 70 kg × 2.2 = 154 lbs.

    What is a stone (unit of weight)?

    A stone is a unit of weight equal to 14 pounds (6.35 kg), used primarily in the UK and Ireland for body weight. A person weighing 11 stone is 154 pounds or 70 kg. The stone is rarely used in scientific or commercial contexts outside the UK; kilograms or pounds are used instead.

    What is the difference between weight and mass in scientific contexts?

    In physics, mass (kg) is intrinsic to the object. Weight (Newtons) is the force of gravity acting on that mass. On Earth's surface, 1 kg of mass has a weight of about 9.81 Newtons. In everyday use, "weight" and "mass" are used interchangeably because we measure them on Earth where gravity is constant.

    How do I convert stone and pounds to kilograms?

    Multiply stones by 14 to get total pounds, then multiply total pounds by 0.4536 to get kilograms. Or: (Stones × 14 + Pounds) × 0.4536. Example: 11 stone 6 pounds = (11×14 + 6) × 0.4536 = (154+6) × 0.4536 = 160 × 0.4536 = 72.6 kg.