Convert Any Unit Instantly With Verified Scientific Accuracy
Get fast and reliable unit conversions across physics, engineering, chemistry, metrology, and everyday measurements. All conversion factors come directly from the SI Brochure (BIPM) and NIST Special Publication 811, ensuring traceability to international standards.
Most Commonly Used Converters
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Common Converters
Everyday measurement conversions including length, mass, temperature, speed, area, time, volume, and pressure units. Ideal for students, professionals, tradespeople, and quick household measurements.
Engineering Converters
Engineering and scientific conversions covering force, torque, energy, power, acceleration, and other physics-derived quantities used in mechanics, materials science, and industrial applications.
Heat / Thermodynamics
Thermodynamic property converters including thermal conductivity, specific heat capacity, heat transfer coefficients, thermal expansion, and fuel efficiency. Suitable for HVAC engineering, chemistry, and material science.
Fluids
Fluid mechanics converters for dynamic viscosity, kinematic viscosity, mass/volume flow rate, permeability, surface tension, and molar concentration. Useful for chemical engineering, hydrodynamics, and environmental science.
Light / Photometry
Photometric and optical converters for luminance, illuminance, luminous intensity, wavelength–frequency calculations, and digital imaging resolution.
Electricity
Electrical unit converters for voltage, resistance, current, charge, inductance, capacitance, conductivity, and electric field strength — essential for electronics and electrical engineering.
Magnetism
Magnetic unit converters including magnetic field strength, magnetic flux, flux density, magnetomotive force, and permeability.
Radiology
Radiological measurement converters for radiation activity, absorbed dose, exposure, and equivalent dose — applicable to medical physics, radiography, and nuclear science.
Fast Access to the Most Requested Conversion Pairs
These popular two-way conversions help you jump directly to the exact measurement you need — no searching required.
How Scientific Unit Conversions Work
Modern measurement systems are based on the International System of Units (SI), which defines seven base quantities: metre (m), kilogram (kg), second (s), ampere (A), kelvin (K), mole (mol), and candela (cd).
All other units — such as newton, pascal, joule, watt, lumen, volt, and ohm — are derived using exact mathematical relationships. For example:
- 1 Newton (N) = 1 kg·m/s²
- 1 Pascal (Pa) = 1 N/m²
- 1 Joule (J) = 1 N·m
- 1 Watt (W) = 1 J/s
This website uses conversion values sourced directly from:
- SI Brochure (BIPM, 9th edition)
- NIST Special Publication 811
- CODATA recommended physical constants
This ensures that all conversions remain traceable, reproducible, and scientifically reliable — suitable for engineering, laboratory, academic, and industrial use.
Frequently Asked Questions
Answers to common questions about how this unit converter works, how accurate it is, and how you can use it in study, engineering, and everyday life.
Where do your conversion factors come from?
Conversion factors are taken from primary scientific references such as the SI Brochure (BIPM) and NIST Special Publication 811, along with CODATA recommended constants where needed. This keeps values aligned with modern metrology standards rather than approximate "back of the envelope" numbers.
How accurate are the results?
Internally, conversions are computed using high-precision factors. Displayed values are rounded to a practical number of decimal places for readability, but the underlying calculations preserve more digits. For critical work, you can increase precision by copying the raw result and adjusting the rounding in your own tools.
Can I link directly to a specific conversion?
Yes. Each converter has dedicated pages for popular unit pairs using URLs like /length/meter-to-foot. You can bookmark or share these links to jump straight into a specific conversion without re-selecting units.
What's the difference between metric, imperial, and US units?
Metric units are based on the SI system (metre, kilogram, litre, etc.). Imperial and US customary systems use units like inch, foot, pound, and gallon. This converter handles both families and clearly labels units so you can move between them without worrying about hidden regional differences.
Is this tool suitable for engineering or academic work?
The data and formulas are designed to be scientifically reliable and are appropriate for homework, lab reports, and professional calculations. However, as with any software tool, you should always verify results before using them in safety-critical or regulatory applications.
Do you support every possible unit?
The focus is on units that are widely used in science, engineering, industry, and education. New units and converter categories are added over time based on user demand. If an important unit is missing, you can note it and it may be included in a future update.