Engineering

Moment of Inertia Converter

Moment of inertia is rotational mass — how hard it is to change an object's spin. The SI unit is the kilogram square meter. Flywheel, motor, and driveline data sheets use kg·m² in metric practice and lb·ft² or slug·ft² in US practice; note that lb·ft² and slug·ft² differ by a factor of about 32.2.

16 units supported Base unit kilogram square meter (kg·m²)

1 kg·m²
23.73036 lb·ft²

Multiply the number of kilogram square meters by 23.7303604042 to get pound square feet. How this is calculated

About moment of inertia conversion

Moment of Inertia conversion is commonly needed when flywheels, servo sizing, driveline design, and robotics. Pound square feet and slug square feet look similar but differ by a factor of about 32.2 — mixing them up is a classic sizing error.

Popular conversions

Convert Kilogram Square Meter to other moment of inertia units

1 kg·m² expressed in every other moment of inertia unit on this site.

  • Kilogram Square Centimeter kg·cm² 10,000
  • Kilogram Square Millimeter kg·mm² 1,000,000
  • Gram Square Meter g·m² 1,000
  • Gram Square Centimeter g·cm² 10,000,000
  • Gram Square Millimeter g·mm² 1,000,000,000
  • Kilogram-force Meter Second² kgf·m·s² 0.10197162
  • Pound Square Foot lb·ft² 23.73036
  • Pound Square Inch lb·in² 3,417.1719
  • Ounce Square Inch oz·in² 54,674.75
  • Slug Square Foot slug·ft² 0.73756215
  • Slug Square Inch slug·in² 106.20895
  • Kilogram-force Centimeter Square Second kgf·cm·s² 10.197162
  • Pound-force Inch Square Second lbf·in·s² 8.8507458
  • Pound-force Foot Second² lbf·ft·s² 0.73756215
  • Ounce-force Inch Second² ozf·in·s² 141.61193

Complete list of moment of inertia units

All 16 units this converter supports, each stated against the kilogram square meter (kg·m²).

16 units

Every moment of inertia unit, stated against the kilogram square meter
Unit Symbol System In kilogram square meters Conversions
Kilogram Square Meter kg·m² SI base unit (kg·m²)
Kilogram Square Centimeter kg·cm² SI 1 kg·cm² = 0.0001 kg·m²
Kilogram Square Millimeter kg·mm² SI 1 kg·mm² = 0.000001 kg·m²
Gram Square Meter g·m² Metric 1 g·m² = 0.001 kg·m²
Gram Square Centimeter g·cm² Metric 1 g·cm² = 1e-7 kg·m²
Gram Square Millimeter g·mm² Metric 1 g·mm² = 1e-9 kg·m²
Kilogram-force Meter Second² kgf·m·s² Metric 1 kgf·m·s² = 9.80665 kg·m²
Pound Square Foot lb·ft² Imperial 1 lb·ft² = 0.0421401100938 kg·m²
Pound Square Inch lb·in² Imperial 1 lb·in² = 0.000292639653429 kg·m²
Ounce Square Inch oz·in² Imperial 1 oz·in² = 0.0000182899783393 kg·m²
Slug Square Foot slug·ft² US 1 slug·ft² = 1.35581794833 kg·m²
Slug Square Inch slug·in² US 1 slug·in² = 0.00941540241896 kg·m²
Kilogram-force Centimeter Square Second kgf·cm·s² Metric 1 kgf·cm·s² = 0.0980665 kg·m²
Pound-force Inch Square Second lbf·in·s² US 1 lbf·in·s² = 0.112984829028 kg·m²
Pound-force Foot Second² lbf·ft·s² US 1 lbf·ft·s² = 1.35581794833 kg·m²
Ounce-force Inch Second² ozf·in·s² US 1 ozf·in·s² = 0.0070615518 kg·m²

Scroll the table sideways to see every column.

Frequently asked questions

What is the base unit for moment of inertia?

Moment of Inertia conversions on this site are calculated against the kilogram square meter (kg·m²).

Which moment of inertia units can I convert?

You can convert between 16 units, including kilogram square meter, kilogram square centimeter, kilogram square millimeter, gram square meter, and more.

Where is moment of inertia conversion useful?

It is commonly needed when flywheels, servo sizing, driveline design, and robotics.

Does this converter mix measurement systems?

The converter supports SI, Metric, Imperial, US units and keeps their exact definitions separate so results stay accurate.

Related categories

Conversion factors are based on internationally agreed unit definitions. See our methodology and sources for details on how these values are verified.