Moment of Inertia Converter
Enter a value and select units to convert
Enter a value and select units to convert
The moment of inertia converter allows you to convert between different units of rotational inertia, from SI units like kilogram square meters to imperial units like slug square feet. This tool is useful for physics, engineering, mechanics, and many fields where rotational dynamics are studied. Moment of inertia is a measure of an object's resistance to changes in its rotational motion.
Common Moment of Inertia Measurement Systems
Metric System (SI)
The International System of Units (SI) uses the kilogram square meter (kg·m²) as the standard unit of moment of inertia.
- Kilogram square meter (kg·m²): The moment of inertia of a 1 kg point mass at a distance of 1 meter from the axis of rotation
- Other metric units are formed by changing the mass unit or the length unit: kg·cm², g·cm², etc.
- 1 kg·m² = 10⁴ kg·cm² = 10⁷ g·cm²
Imperial/US Customary System
Used primarily in the United States and a few other countries.
- Slug square foot (slug·ft²): The imperial unit of moment of inertia
- Pound square foot (lbf·ft²): Another commonly used unit, especially in engineering
- Pound square inch (lbf·in²): Used for smaller rotational systems
- 1 slug·ft² = 1.35582 kg·m²
Other Units
Various specialized units of moment of inertia.
- Ounce square inch (oz·in²): Used for very small rotational systems
- Ounce square foot (oz·ft²): Sometimes used in specific applications
Applications
Moment of inertia is critical in many applications:
- Mechanical engineering: Design of rotating machinery, flywheels, and balancing systems
- Structural engineering: Analysis of beams and structures under torsional loads
- Robotics: Control of robotic arms and joints
- Aerospace engineering: Aircraft and spacecraft stability analysis
- Vehicle dynamics: Handling characteristics of automobiles
Common Moment of Inertia Conversions
| From | To | Multiply By |
|---|---|---|
| Kilogram square meter (kg·m²) | Kilogram square centimeter (kg·cm²) | 10,000 |
| Kilogram square meter (kg·m²) | Gram square centimeter (g·cm²) | 10,000,000 |
| Kilogram square meter (kg·m²) | Slug square foot (slug·ft²) | 0.737562 |
| Kilogram square meter (kg·m²) | Pound square foot (lbf·ft²) | 23.7304 |
| Gram square centimeter (g·cm²) | Kilogram square meter (kg·m²) | 0.0000001 |
| Slug square foot (slug·ft²) | Kilogram square meter (kg·m²) | 1.35582 |
| Pound square foot (lbf·ft²) | Kilogram square meter (kg·m²) | 0.042140 |
| Pound square inch (lbf·in²) | Kilogram square meter (kg·m²) | 0.000292639 |
| Ounce square inch (oz·in²) | Kilogram square meter (kg·m²) | 0.0000182899 |
| Kilogram square centimeter (kg·cm²) | Kilogram square meter (kg·m²) | 0.0001 |