Mass Converter
Free Mass Calculator for conversions & measurement. Enter values to get step-by-step solutions with formulas and graphs.
Reviewed by Manoj Kumar, Mathematics Educator
Formula
target_value = input_value * (input_to_kg / target_to_kg)
Mass conversion works by first converting the input value to kilograms using a known conversion factor, then dividing by the target unit conversion factor. For example, to convert pounds to grams: first multiply by 0.453592 to get kg, then divide by 0.001 to get grams.
Worked Examples
Example 1: Converting 1 Kilogram to All Units
Problem:Convert 1 kilogram to grams, pounds, ounces, stones, troy ounces, carats, and grains.
Solution:1 kg = 1000 g\n1 kg = 2.2046 lb\n1 kg = 35.2740 oz\n1 kg = 0.1575 st\n1 kg = 32.1507 oz t\n1 kg = 5000 ct\n1 kg = 15432.3584 gr
Result:1 kg = 1000 g = 2.2046 lb = 35.2740 oz = 5000 ct
Example 2: Converting 150 Pounds to Metric
Problem:A person weighs 150 pounds. Convert to kilograms, stones, and metric tons.
Solution:Kilograms = 150 * 0.45359237 = 68.0389 kg\nStones = 150 / 14 = 10.7143 st\nMetric Tons = 68.0389 / 1000 = 0.0680 t\nGrams = 68038.86 g
Result:150 lb = 68.0389 kg = 10.7143 st = 0.0680 metric tons
Frequently Asked Questions
What is the difference between mass and weight?
Mass is a fundamental property of matter that measures the amount of substance in an object, while weight is the force exerted on that mass by gravity. Mass remains constant regardless of location (measured in kilograms), but weight changes depending on gravitational field strength (measured in newtons). On the Moon, your mass stays the same but you weigh about one-sixth of your Earth weight because the Moon gravitational pull is weaker. In everyday language, people often use mass and weight interchangeably, but in physics and engineering, the distinction is crucial. A 70 kg person has a weight of about 686 newtons on Earth but only 114 newtons on the Moon.
Why is the kilogram the SI base unit of mass?
The kilogram became the SI base unit of mass as part of the metric system established during the French Revolution in the 1790s. Originally defined as the mass of one liter of water at 4 degrees Celsius, it was later represented by a physical artifact called the International Prototype of the Kilogram (IPK), a platinum-iridium cylinder stored in Paris. In 2019, the kilogram was redefined based on the Planck constant, making it the last SI unit to be defined by a fundamental physical constant rather than a physical object. This change ensures that the kilogram definition will never drift over time due to surface contamination or wear of a physical standard.
How do you convert between metric and imperial mass units?
The key conversion factors between metric and imperial systems are: 1 kilogram equals 2.20462 pounds, and 1 pound equals 0.453592 kilograms. From these, you can derive other conversions: 1 ounce equals 28.3495 grams, 1 stone equals 6.35029 kilograms (14 pounds), and 1 metric ton equals 2204.62 pounds. For quick mental math, multiply kilograms by 2.2 to get approximate pounds, or divide pounds by 2.2 to get approximate kilograms. A useful benchmark is that 1 kilogram is roughly the mass of a liter of water, while 1 pound is about the mass of a medium apple or a baseball.
What is a grain as a unit of mass?
A grain is one of the oldest units of mass measurement, originally based on the mass of a single grain of barley or wheat. One grain equals exactly 64.79891 milligrams. Despite its antiquity, the grain remains actively used today in several fields: in pharmacy and medicine for precise drug dosages (aspirin tablets are often 5 grains or 325 mg), in ballistics for measuring bullet and powder charge weights (a typical 9mm bullet weighs about 115 grains), and in precious metals trading. The grain is the same unit in both the avoirdupois and troy systems, serving as a bridge between these two otherwise incompatible measurement systems.
References
Reviewed by Manoj Kumar, Mathematics Educator · Editorial policy