Engineering reference

Technical unit workspace

Quantities: 7
Systems: SI / US

Engineering Unit Info

Common engineering units:

Length: meter (m), foot (ft), inch (in)
Mass: kilogram (kg), pound (lb), ton
Force: newton (N), pound-force (lbf)
Pressure: pascal (Pa), PSI, bar
Velocity: m/s, mph, km/h

Key relationships:

1 m = 3.28084 ft = 39.3701 in
1 kg = 2.20462 lb
1 N = 0.224809 lbf
1 Pa = 0.000145038 PSI

SI System:

The International System of Units (SI) evolved from the metric system established during the French Revolution. It was officially established in 1960 to standardize scientific measurements globally.

Imperial System:

The Imperial system originated in the British Empire with roots in ancient Roman, Anglo-Saxon, and Germanic measurements. It was standardized in the British Weights and Measures Act of 1824.

Engineering Units:

Engineering-specific units developed alongside industrial progress in the 18th and 19th centuries, with the horsepower unit created by James Watt to compare steam engines to horses.

Mechanical Engineering:

Stress/strain calculations (Pa, PSI)
Torque measurements (N⋅m, lbf⋅ft)
Velocity and acceleration (m/s, ft/s²)
Material properties (kg/m³, lb/ft³)

Civil Engineering:

Structural load calculations (kN, ton)
Distance and area measurements (m, ft²)
Fluid flow rates (m³/s, gal/min)
Concrete strength (MPa, PSI)

Other Fields:

Electrical: voltage, current, resistance
Chemical: concentration, reaction rates
Aerospace: thrust, lift, drag forces

Engineering Conversion Calculator

Formula verified

Formula verifiedLive calculation

Quick answer

Live calculation

1 RPM=0.10472 rad/s

Formula: rad/s = RPM x 0.10472

Converting Revolution per Minute to Radian per Second with 6-place display precision.

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Quick pairs

Jump to the most common unit combinations

Quantity

Velocity - Angular

Input unit

Revolution per Minute (RPM)

Output unit

Radian per Second (rad/s)

Engineering pair converters

Open the published force, pressure, power, and length pair pages used most often in engineering work.

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What are Engineering Units?

Engineering units are standardized measurements used in technical fields to quantify physical properties. These units form the foundation of engineering calculations, designing systems, and ensuring safety and compatibility across different regions.

The two primary systems are SI (International System) and Imperial/US Customary. SI units are based on the metric system and are used globally, while Imperial units are common in the US and some other regions. Understanding conversions between these systems is essential for engineers working internationally.

Common Engineering Conversions

Type	SI Unit	Imperial/US Unit	Conversion Factor
Length	1 meter (m)	feet (ft)	1 m = 3.28084 ft
Length	1 meter (m)	inches (in)	1 m = 39.3701 in
Mass	1 kilogram (kg)	pounds (lb)	1 kg = 2.20462 lb
Force	1 newton (N)	pound-force (lbf)	1 N = 0.224809 lbf
Pressure	1 pascal (Pa)	PSI	1 Pa = 0.000145038 PSI
Torque	1 newton-meter (N⋅m)	foot-pound (ft⋅lb)	1 N⋅m = 0.737562 ft⋅lb
Power	1 watt (W)	horsepower (hp)	1 W = 0.00134102 hp

Derived Unit Conversions

Physical Quantity	SI Unit	Alternative Unit	Conversion
Area	square meter (m²)	square foot (ft²)	1 m² = 10.7639 ft²
Volume	cubic meter (m³)	cubic foot (ft³)	1 m³ = 35.3147 ft³
Velocity	meters per second (m/s)	miles per hour (mph)	1 m/s = 2.23694 mph

Practical Applications of Engineering Conversions

Manufacturing & Production

Converting machine specifications between metric and imperial
Calculating material requirements for international production
Ensuring component interchangeability across global supply chains
Translating technical drawings between measurement systems

Structural Engineering

Converting load calculations between newtons and pounds-force
Analyzing stress and strain in different unit systems
Calculating material strengths and safety factors
Designing structures to international building codes

Energy & Power Systems

Converting between watts, BTUs, and horsepower
Calculating heat transfer and thermal efficiency
Sizing motors and power distribution systems
Analyzing energy consumption and efficiency metrics

Aerospace & Defense

Converting thrust, lift, and drag forces between unit systems
Calculating fuel consumption rates and mission requirements
Ensuring international compatibility for avionics
Meeting different national and international standards

Research & Development

Converting experimental data between different unit systems
Standardizing measurements for international publications
Comparing results from different testing procedures
Developing products for global markets with varied standards

Educational Resource

This popular educational video explains engineering unit conversions with a clear, step-by-step approach. With millions of views, it covers the dimensional analysis method used by engineers to convert between different measurement systems, making it easier to understand how to handle complex engineering unit conversions.

Engineering Conversion Resources

Open Engineering Chart Pack (pressure, power, length)Download Engineering Conversion Chart (PDF)

Get our comprehensive engineering conversion chart showing key unit conversions for length, mass, force, pressure, and more for quick reference in your engineering projects and calculations.

Related Conversion Tools:

Engineering Conversion FAQs

Find answers to common questions about engineering measurements and conversions.

What are the fundamental engineering units and their conversions?

The fundamental engineering units and their common conversions are: 1) Length: meters to feet, inches to millimeters, 2) Mass: kilograms to pounds, grams to ounces, 3) Force: newtons to pounds-force, 4) Pressure: pascals to PSI, 5) Temperature: Celsius to Fahrenheit, 6) Time: seconds to hours, 7) Energy: joules to BTU.

How do you perform accurate engineering unit conversions?

To perform accurate engineering conversions: 1) Write down both units and their dimensions, 2) Find the appropriate conversion factor, 3) Set up the equation to cancel out units, 4) Perform the calculation, 5) Verify units are correct, 6) Round to appropriate significant figures. Always document conversion factors used.

What is the difference between SI and Imperial units in engineering?

SI (International System) and Imperial units differ in several ways: 1) SI uses metric system (meters, kilograms), 2) Imperial uses traditional units (feet, pounds), 3) SI is standard in most countries and scientific work, 4) Imperial is common in US industry, 5) SI uses base-10 scaling, while Imperial uses various ratios.

Why are unit conversions important in engineering?

Unit conversions are crucial in engineering because: 1) International projects use different systems, 2) Safety calculations require precise measurements, 3) Material specifications vary by region, 4) Manufacturing standards differ globally, 5) Engineering software may require specific units, 6) Cost calculations depend on correct unit conversion.

What are derived units in engineering?

Derived units combine base units to express complex quantities: 1) Velocity uses length/time (m/s), 2) Acceleration uses velocity/time (m/s²), 3) Force combines mass and acceleration (N = kg⋅m/s²), 4) Pressure is force/area (Pa = N/m²), 5) Energy involves force and distance (J = N⋅m).

Engineering conversion shortcuts

Move between the engineering hub and high-value force, pressure and power calculators.