Conversion method
Mass moment of inertia depends on mass distribution and axis. This is not the second moment of area used for beam sections.
kg·cm² = x × 10000
10 kg·m² = 100000 kg·cm².
| kg·m² | kg·cm² |
|---|---|
| 1 | 10000 |
| 5 | 50000 |
| 10 | 100000 |
| 25 | 250000 |
| 50 | 500000 |
| 100 | 1000000 |
Unit definitions and sources
Mass moment of inertia depends on mass distribution and axis. This is not the second moment of area used for beam sections.
| Unit and system | Use | Definition | Relationship |
|---|---|---|---|
| Kilogram square meter (kg·m²); si | Common units | Kilogram square meter: base (kg-m2) = value × 1. Common use: Moment of Inertia. Source checked 2026-09-20 (implementation review). | Exact definition; numerical display may be rounded |
| Kilogram square centimeter (kg·cm²); si | Common units | Kilogram square centimeter: base (kg-m2) = value × 0.0001. Common use: Moment of Inertia. Source checked 2026-09-20 (implementation review). | Exact definition; numerical display may be rounded |
| Gram square centimeter (g·cm²); si | Specialist units | Gram square centimeter: base (kg-m2) = value × 1e-07. Common use: Moment of Inertia. Source checked 2026-09-20 (implementation review). | Exact definition; numerical display may be rounded |
| Pound square foot (lb·ft²); si | Specialist units | Pound square foot: base (kg-m2) = value × 0.042140110093804806. Common use: Moment of Inertia. Source checked 2026-09-20 (implementation review). | Exact definition; numerical display may be rounded |
| Pound square inch (lb·in²); si | Specialist units | Pound square inch: base (kg-m2) = value × 0.0002926396534292. Common use: Moment of Inertia. Source checked 2026-09-20 (implementation review). | Exact definition; numerical display may be rounded |
| Kilogram square millimeter (kg·mm²); other | Specialist units | kilogram square millimeter = 1e-06 kg-m2, derived from the component SI/customary definitions. Common use: Moment of Inertia. Source checked 2026-09-20 (implementation review). | Exact definition; numerical display may be rounded |
| Gram square millimeter (g·mm²); other | Specialist units | gram square millimeter = 1e-09 kg-m2, derived from the component SI/customary definitions. Common use: Moment of Inertia. Source checked 2026-09-20 (implementation review). | Exact definition; numerical display may be rounded |
| Kilogram-force meter square second (kgf·m·s²); other | Specialist units | kilogram-force meter square second = 9.80665 kg-m2, derived from the component SI/customary definitions. Common use: Moment of Inertia. Source checked 2026-09-20 (implementation review). | Exact definition; numerical display may be rounded |
| Kilogram-force centimeter square second (kgf·cm·s²); other | Specialist units | kilogram-force centimeter square second = 0.0980665 kg-m2, derived from the component SI/customary definitions. Common use: Moment of Inertia. Source checked 2026-09-20 (implementation review). | Exact definition; numerical display may be rounded |
| Ounce square inch (oz·in²); other | Specialist units | ounce square inch = 1.8289978339325e-05 kg-m2, derived from the component SI/customary definitions. Common use: Moment of Inertia. Source checked 2026-09-20 (implementation review). | Exact definition; numerical display may be rounded |
| Ounce-force inch sq. second (ozf·in·s²); other | Specialist units | ounce-force inch sq. second = 0.007061551814226043 kg-m2, derived from the component SI/customary definitions. Common use: Moment of Inertia. Source checked 2026-09-20 (implementation review). | Exact definition; numerical display may be rounded |
| Pound-force foot sq. second (lbf·ft·s²); other | Specialist units | pound-force foot sq. second = 1.3558179483314003 kg-m2, derived from the component SI/customary definitions. Common use: Moment of Inertia. Source checked 2026-09-20 (implementation review). | Exact definition; numerical display may be rounded |
| Pound-force inch sq. second (lbf·in·s²); other | Specialist units | pound-force inch sq. second = 0.11298482902761668 kg-m2, derived from the component SI/customary definitions. Common use: Moment of Inertia. Source checked 2026-09-20 (implementation review). | Exact definition; numerical display may be rounded |
Sources: NIST: SP 811 Appendix B.8: conversion factors; BIPM: SI prefixes
Precision of moment of inertia conversions
All 13 moment of inertia units convert through Kilogram square meter (kg·m²). 13 have an exact defined relationship to the base unit and 0 are conventional or measured values. Results and the tables on this page come from the same engine, so a table value can be checked against the converter directly.
Standard display shows up to six decimal places, switching to scientific notation for very large or small values. Calculation uses JavaScript binary floating point independently of display rounding, so extra digits are not a claim about measurement accuracy. Each unit lists its own source; a citation records where the definition comes from, not an independent review. See Conversion methodology for the review and correction process.