Density Converter
Free Density Converter — convert kg/m³, g/cm³, g/mL, lb/ft³, lb/gal instantly with interactive chart and breakdown table for accurate scientific conversion.
About This Calculator
The Density Converter is a free online tool that lets you instantly convert between the most commonly used density units worldwide. Whether you are a student studying physics or chemistry, an engineer working with material properties, a scientist conducting research, or a professional in manufacturing or construction, this converter helps you quickly translate density values between metric and imperial systems without manual calculations.
The converter supports five density units: kilograms per cubic meter (kg/m³), grams per cubic centimeter (g/cm³), grams per milliliter (g/mL), pounds per cubic foot (lb/ft³), and pounds per US gallon (lb/gal). Kilograms per cubic meter is the SI (International System of Units) standard for density measurement, used universally across scientific and technical fields. The converter works by first converting your input value to the base unit (kg/m³) using precise conversion factors, then converting that base value to your chosen target unit. For example, 1 g/cm³ equals exactly 1,000 kg/m³ because there are 1,000 grams in a kilogram and 1,000,000 cubic centimeters in a cubic meter (1,000 / 0.000001 = 1,000,000,000 / 1,000,000 = 1,000). The converter uses scientifically accepted factors: 1 g/cm³ = 1,000 kg/m³, 1 g/mL = 1,000 kg/m³, 1 lb/ft³ = 16.0185 kg/m³, and 1 lb/gal = 119.827 kg/m³.
Regional Notes
In India and the UK, density is commonly expressed in kg/m³ and g/cm³ following the metric system used in education, engineering, and industry. Laboratory measurements and textbooks use g/cm³ for solids and liquids while gases are measured in kg/m³. In the United States, imperial density units like lb/ft³ and lb/gal are still widely used in construction, manufacturing, and everyday applications — for example, the density of concrete is typically specified in lb/ft³. The US customary system defines the pound per gallon based on the US liquid gallon of 231 cubic inches. This converter supports all these regional preferences in a single interface with an interactive chart showing your value across every unit simultaneously.
Frequently Asked Questions
How does the Density Converter work?
Enter a numeric density value, select the source unit from the From dropdown, choose the target unit from the To dropdown, and click Convert. The calculator converts the value using precise conversion factors — kg/m³ is the SI base unit, and all other units are converted relative to it. A bar chart compares the value across all supported units, and a breakdown table shows the exact result in every unit.
What density units are supported?
The converter supports five density units: kilograms per cubic meter (kg/m³), grams per cubic centimeter (g/cm³), grams per milliliter (g/mL), pounds per cubic foot (lb/ft³), and pounds per US gallon (lb/gal). These cover the most common metric and imperial units used worldwide in science, engineering, and industry.
What is the density of water in different units?
At 4°C (39.2°F), the density of water is exactly 1 g/cm³, which equals 1,000 kg/m³, 1 g/mL, approximately 62.43 lb/ft³, and approximately 8.345 lb/US gal. Water reaches its maximum density at 4°C and becomes less dense as temperature moves away from this point.
Is the conversion accurate?
Yes, all conversions use scientifically accepted and internationally standardized conversion factors. The results are accurate to six decimal places for small values and four decimal places for larger values, ensuring precision for scientific, engineering, and educational applications.
How do I convert between kg/m³ and g/cm³?
To convert kg/m³ to g/cm³, divide by 1,000. For example, 1,000 kg/m³ = 1 g/cm³. Conversely, multiply g/cm³ by 1,000 to get kg/m³. The converter handles this automatically — simply select kg/m³ as the source and g/cm³ as the target, or vice versa, and enter your value.
What is density and how is it measured?
Density (symbol: ρ) is the mass of a substance divided by its volume, typically expressed in kg/m³. It is measured using hydrometers, pycnometers, or by directly measuring mass and volume and calculating the ratio. It is an intensive property meaning it does not depend on the amount of substance — pure water always has a density of approximately 1 g/cm³ at 4°C regardless of sample size.
How does temperature affect density?
Most substances expand when heated and contract when cooled, causing density to decrease with increasing temperature and increase with decreasing temperature. Water is an exception between 0°C and 4°C — it becomes denser as temperature rises in this range, reaching maximum density at 4°C. This anomaly causes ice to float and affects lake stratification in winter.
Can I use this for cooking measurements?
Yes, you can use the density converter to convert between g/mL and other units, which is useful for recipe ingredient conversions. However, cooking ingredients like flour, sugar, and butter have different densities — this converter uses standard density unit conversions, not ingredient-specific density values. For ingredient-specific conversions, use a dedicated cooking converter.