Skip to main content

Convert Slug-feet squared to Pound-inches squared

Instantly convert Slug-feet squared (slug·ft²) to Pound-inches squared (lb·in²) with our free online calculator.

Reviewed by Christopher FloiedUpdated

Formula: slug·ft² to lb·in²multiply by 4633.06

Reference Table

Slug-feet squared (slug·ft²)Pound-inches squared (lb·in²)
14633.06
523165.3
1046330.6
25115827
50231653
100463306

How to Convert Slug-feet squared to Pound-inches squared

Formula

To convert Slug-feet squared (slug·ft²) to Pound-inches squared (lb·in²): multiply by 4633.06

Step-by-Step

  1. Start with your value in Slug-feet squared (slug·ft²).
  2. Multiply by 4633.06 to perform the conversion.
  3. The result is your value expressed in Pound-inches squared (lb·in²).

Conversion Factor

1 slug·ft² = 4633.06 lb·in²

Reverse Factor

1 lb·in² = 0.00021584 slug·ft²

Worked Example

Convert 25 Slug-feet squared to Pound-inches squared: 25 slug·ft² = 115827 lb·in²

About Slug-foot squared (slug·ft²)

A US aerospace mass-moment-of-inertia unit (1 slug·ft² ≈ 1.35582 kg·m² per NIST SP 811). Because US aerospace engineers keep Newton's second law F = m·a (and its rotational analog τ = I·α) dimensionally consistent in imperial units without inserting a gravitational-constant factor gc by using slugs as the mass unit, aircraft and missile inertia properties are reported in slug·ft² in flight-dynamics textbooks (Etkin & Reid, Stevens-Lewis-Johnson, Roskam), stability derivative tables, simulation data decks (FlightGear, X-Plane, MATLAB Aerospace Toolbox), and FAR Part 25 transport-category aircraft type-certificate data sheets. Reference values: Boeing 737 roll inertia Ixx ≈ 1.8 × 10⁶ slug·ft²; pitch inertia Iyy ≈ 1.3 × 10⁷ slug·ft²; yaw inertia Izz ≈ 1.5 × 10⁷ slug·ft². Cessna 172 Ixx ≈ 1,285 slug·ft². Convert slug·ft² to kg·m² by multiplying by 1.3558.

About Pound-inch squared (lb·in²)

An imperial mass-moment-of-inertia unit using pound-mass per inch² (≈ 2.926 × 10⁻⁴ kg·m² per NIST SP 811 = exactly 1/144 of lb·ft² since 1 ft² = 144 in²). Used for smaller rotating components in US mechanical engineering where lb·ft² would produce awkwardly-small decimal values: servo and stepper motor shafts (US-built servos from Kollmorgen, Allen-Bradley, Parker often spec rotor inertia in lb·in² for export-compatible documentation), small flywheels in instrumentation and precision-mechanism design, engine valvetrain components (poppet-valve + spring + retainer + rocker arm assembly inertia for high-RPM engine valve-bounce analysis per SAE J1857), aerospace small-component inertia in legacy US-edition stress reports, and CNC-spindle drive-train inertia for servo-tuning calculations. Convert lb·in² to kg·m² by multiplying by 2.926 × 10⁻⁴; to lb·ft² by dividing by 144; to kg·cm² by multiplying by 2.926.

Quick Facts

  • 1 Slug-foot squared equals 4633.06 Pound-inches squared
  • 1 Pound-inch squared equals 0.00021584 Slug-feet squared
  • Slug-foot squared is a unit of mass moment of inertia
  • Pound-inch squared is a unit of mass moment of inertia
  • This conversion is commonly used in rotational dynamics, flywheel design, and robotics
  • The Slug-foot squared belongs to the imperial system

Common Slug-foot squared to Pound-inch squared Conversions

Slug-feet squared (slug·ft²)Pound-inches squared (lb·in²)
0.0146.3306
0.1463.306
0.251158.27
0.52316.53
14633.06
29266.13
313899.2
523165.3
1046330.6
1569496
2092661.3
25115827
50231653
75347480
100463306
2501158270
5002316530
10004633060
500023165300
1000046330600

Understanding Slug-feet squared

The Slug-foot squared (symbol: slug·ft²) is a unit of mass moment of inertia. A US aerospace mass-moment-of-inertia unit (1 slug·ft² ≈ 1.35582 kg·m² per NIST SP 811). Because US aerospace engineers keep Newton's second law F = m·a (and its rotational analog τ = I·α) dimensionally consistent in imperial units without inserting a gravitational-constant factor gc by using slugs as the mass unit, aircraft and missile inertia properties are reported in slug·ft² in flight-dynamics textbooks (Etkin & Reid, Stevens-Lewis-Johnson, Roskam), stability derivative tables, simulation data decks (FlightGear, X-Plane, MATLAB Aerospace Toolbox), and FAR Part 25 transport-category aircraft type-certificate data sheets. Reference values: Boeing 737 roll inertia Ixx ≈ 1.8 × 10⁶ slug·ft²; pitch inertia Iyy ≈ 1.3 × 10⁷ slug·ft²; yaw inertia Izz ≈ 1.5 × 10⁷ slug·ft². Cessna 172 Ixx ≈ 1,285 slug·ft². Convert slug·ft² to kg·m² by multiplying by 1.3558.

It belongs to the imperial measurement system.

Slug-feet squared are commonly used in rotational dynamics, flywheel design, and robotics.

Understanding Pound-inches squared

The Pound-inch squared (symbol: lb·in²) is a unit of mass moment of inertia. An imperial mass-moment-of-inertia unit using pound-mass per inch² (≈ 2.926 × 10⁻⁴ kg·m² per NIST SP 811 = exactly 1/144 of lb·ft² since 1 ft² = 144 in²). Used for smaller rotating components in US mechanical engineering where lb·ft² would produce awkwardly-small decimal values: servo and stepper motor shafts (US-built servos from Kollmorgen, Allen-Bradley, Parker often spec rotor inertia in lb·in² for export-compatible documentation), small flywheels in instrumentation and precision-mechanism design, engine valvetrain components (poppet-valve + spring + retainer + rocker arm assembly inertia for high-RPM engine valve-bounce analysis per SAE J1857), aerospace small-component inertia in legacy US-edition stress reports, and CNC-spindle drive-train inertia for servo-tuning calculations. Convert lb·in² to kg·m² by multiplying by 2.926 × 10⁻⁴; to lb·ft² by dividing by 144; to kg·cm² by multiplying by 2.926.

It belongs to the imperial measurement system.

Pound-inches squared are commonly used in rotational dynamics, flywheel design, and robotics.

Why Convert Slug-feet squared to Pound-inches squared?

Converting between Slug-feet squared and Pound-inches squared is a frequent requirement for engineers, scientists, and students working with mass moment of inertia values. Different industries and regions favour different unit systems, so having a dependable conversion tool saves time and prevents errors in technical calculations. Whether you are verifying a specification sheet, cross-checking simulation results, or preparing a report for an international audience, accurate mass moment of inertia conversion is essential.

Frequently Asked Questions

How do I convert Slug-feet squared to Pound-inches squared?

A US aerospace mass-moment-of-inertia unit (1 slug·ft² ≈ 1. To convert Slug-feet squared to Pound-inches squared, multiply by 4633.06. For example, 25 slug·ft² equals 115827 lb·in².

How many Pound-inches squared are in 1 Slug-foot squared?

There are 4633.06 Pound-inches squared in 1 Slug-foot squared.

How many Slug-feet squared are in 1 Pound-inch squared?

There are 0.00021584 Slug-feet squared in 1 Pound-inch squared.

What is the formula for Slug-foot squared to Pound-inch squared conversion?

The formula is: multiply by 4633.06. This means 1 slug·ft² = 4633.06 lb·in².

Is a Slug-foot squared bigger than a Pound-inch squared?

No. One Slug-foot squared is smaller than one Pound-inch squared because 1 slug·ft² equals 4633.06 lb·in², which is greater than 1.

When do you need to convert between Slug-feet squared and Pound-inches squared?

An imperial mass-moment-of-inertia unit using pound-mass per inch² (≈ 2. Slug-foot squared and Pound-inch squared are both mass moment units, so conversion comes up whenever one source of information uses one unit and another uses the other — a classic cross-reference challenge in engineering, trade, travel, and everyday life.

More Mass Moment of Inertia Conversions

Related Tools