Unit Conversion Calculator
Convert between common engineering units quickly and accurately.
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About Unit Conversion
This calculator handles the most common engineering unit conversions. All conversion factors are based on international standards (SI, IEC, ASTM).
Engineering Unit Conversion Guide
Unit conversion is a fundamental skill in engineering. Whether you're reading a datasheet from a different country, checking a specification in non-SI units, or verifying calculations, accurate unit conversion prevents costly mistakes.
Common Conversion Categories
- Length: Convert between metric (mm, cm, m, km) and imperial (in, ft, yd, mi) units. Essential for mechanical design and construction.
- Area: Convert between mm², m², in², ft², acres, and hectares. Used in land measurement and PCB design.
- Volume: Convert between liters, gallons, m³, and ft³. Common in fluid dynamics and chemical engineering.
- Pressure: Convert between Pa, bar, atm, psi, and mmHg. Critical for HVAC, hydraulic systems, and process engineering.
- Temperature: Convert between Celsius, Fahrenheit, and Kelvin. Unlike other conversions, temperature uses non-linear formulas: °F = °C × 9/5 + 32, K = °C + 273.15
- Energy: Convert between joules, kWh, BTU, and calories. Important for power systems and thermodynamics.
Engineering Applications
- International projects: Convert between metric and imperial units when working with suppliers or standards from different regions.
- Datasheet interpretation: Many component datasheets use mixed units — this tool helps you normalize them for comparison.
- Thermal management: Convert thermal resistance (°C/W) and thermal conductivity units for heatsink calculations.
- Power systems: Convert between kVA, kW, and kVAR; between different voltage standards (120V/240V systems).
Frequently Asked Questions
Why is temperature conversion different from other units?
Temperature scales have different zero points. Celsius defines 0° as the freezing point of water, Fahrenheit defines 32° as the same point, and Kelvin starts at absolute zero (-273.15°C). This means temperature conversion requires offset formulas, not just multiplication factors.
What is the difference between mass and weight?
Mass is the amount of matter in an object (measured in kg), while weight is the force exerted by gravity on that mass (measured in newtons). On Earth, a 1 kg mass weighs approximately 9.81 N. In everyday use, "weight" often refers to mass, which is why this converter groups them together.
Are these conversion factors exact or approximate?
Most conversion factors are based on exact international definitions (1 inch = 25.4 mm exactly, 1 pound = 0.45359237 kg exactly). Some historical units may use commonly accepted approximations. All factors comply with SI, IEC, and ASTM standards.