Weight Converter

This page converts a mass from one unit into another. Every value passes through the kilogram, the SI unit mass is held in, and mass stays mass: a unit only converts inside its own dimension.

How do you convert a weight between kilograms, pounds and stone?

Pick the unit you have, pick the unit you want, and type the value. The page multiplies by the factor between the two and prints the arithmetic under the result, so the answer and the working are the same object.

1. Choose the unit your value is in. This page opens on the kilogram.
2. Choose the unit you want it in. This page opens on the pound.
3. Type the value. The result and the factor behind it appear together.
4. Read the working. It converts into the kilogram first and out again, which is the same two lines you would write by hand.

Mass Conversion Table

One row per unit this page offers, each measured against the kilogram. The last column says whether the factor is a definition or a reading of one.

Worked Examples

The questions the bank ranked highest for this page, answered with the working.

Where These Factors Come From

Every number above is read from the knowledge base rather than computed for the page. These are the statements it holds for mass.

• One avoirdupois pound is exactly 0.45359237 kg. One ounce is a sixteenth of a pound, 0.028349523125 kg, and one stone is fourteen pounds, 6.35029318 kg.
• A kilogram measures mass; a newton measures weight, the force gravity exerts on that mass. This page scales mass, so its result does not change with location.
• An exact factor is a definition rather than a measurement. 1 in = 25.4 mm and 1 lb = 0.45359237 kg were fixed by the 1959 international yard and pound agreement, so they never gain another digit.
• standard acceleration of free fall, value 9.80665
• How this page reports a result result as a mass in the target unit; no local gravity is applied

SI prefixes on this page

Is It Mass or Weight?

Everything on this page is a mass. Weight is a force and depends on where the measurement is taken; a kilogram of flour holds the same mass anywhere, and no local gravity is applied to any result here.

The rule behind this factor is the same for every unit - what makes a factor exact.

Frequently Asked Questions

Related Conversions

• Pressure sits in the same measurement group as mass - read a pressure in another unit.
• Torque sits in the same measurement group as mass - torque in newton-metres, pound-feet and kilogram-force metres.
• Pace sits in the same measurement group as mass - minutes per kilometre and minutes per mile.
• Speed sits in the same measurement group as mass - speed in metres per second, km/h, mph and knots.
• If you are measuring volumetric flow rate rather than mass, volume passing per unit of time instead.
• If you are measuring power rather than mass, energy delivered per second instead.

The rest of the family sits on pick another quantity to convert.