Transparent method
The formula
Worked example
Example inputs
How to interpret the result
Weight and mass are treated as interchangeable in everyday conversation and in this calculator, which is accurate enough for cooking, shipping and daily life but technically imprecise. Mass stays constant everywhere, while weight is actually a force that changes slightly with local gravity, a distinction that matters in physics but not in an everyday conversion.
Before you rely on it
What to check
Confirm which unit pair you're converting between, since some, like stone, aren't part of the everyday system many readers grew up using and are easy to misjudge by size.
The common error
Where people go wrong with weight converter calculator
Assuming every weight unit scales the same way relative to a kilogram. Stone, for instance, equals fourteen pounds, not ten or some other round number, and guessing at unfamiliar unit sizes produces confidently wrong results.
Sensitivity evidence
How value changes the converted value
| Value | Converted value | 1 unit of "to" in "from" units |
|---|---|---|
| 120 | 54.4 | 2.2 |
| 135 | 61.2 | 2.2 |
| 150worked example | 68 | 2.2 |
| 165 | 74.8 | 2.2 |
| 180 | 81.6 | 2.2 |
Every input, tested
Which input moves the converted value most
| Input | Tested from | To | Converted value at each end | Swing |
|---|---|---|---|---|
| From | Grams | US short tons | 0.15 to 136,077.7 | 136,077.6 (220462%) |
| To | Grams | US short tons | 68,038.8 to 0.075 | 68,038.7 (100000%) |
| Value | 135 | 165 | 61.2 to 74.8 | 13.6 (20%) |
Step by step
The worked example, input by input
| Input | Value used | What it means |
|---|---|---|
| Value | 150 | |
| From | Pounds | Unit to convert from. |
| To | Kilograms | Unit to convert to. |
| Converted value | 68 | |
| 1 unit of "to" in "from" units | 2.2 | |
Inputs, definitions and assumptions
Value
From
Unit to convert from.
To
Unit to convert to.
Where the inputs come from
Enter the value and select the units to convert between: grams, kilograms, pounds, ounces, stone and metric tons. In everyday use weight and mass are treated as the same thing, and the converter uses mass units. Read the value from a scale or a package label, and note whether the unit is pounds or ounces. One pound is defined as exactly 0.45359237 kilograms.
When the result stops applying
Ounces of weight differ from fluid ounces of volume. Scales have their own error, so a precise conversion does not make a measurement more accurate.
What to compare it with
Convert volumes on the volume converter, lengths on the length converter, and forces on the force converter, where weight is treated as a force. The BMI, ideal weight and calories pages use pounds and kilograms, and the density calculator relates mass and volume.
People also ask
Frequently asked questions
How many pounds are in a kilogram?
About 2.205 pounds. One kilogram equals 2.20462 pounds.
What is a stone?
A British unit of weight equal to 14 pounds, still used for body weight in the United Kingdom and Ireland.
Is a ton the same everywhere?
No. A metric ton is 1,000 kilograms, a US short ton is 2,000 pounds and a UK long ton is 2,240 pounds.