Convert between CGS and SI units for force, energy, pressure, viscosity, magnetic fields, and more. Covers dyne, erg, gauss, poise, stokes, barye, and all major CGS quantities.
The centimetre-gram-second (CGS) system of units was the dominant measurement system in physics for over a century before the International System of Units (SI) became the global standard. Many older textbooks, research papers, and specialized fields — particularly electromagnetism and astrophysics — still use CGS units like the dyne, erg, gauss, poise, and stokes. Converting between CGS and SI is essential when working with legacy literature or cross-referencing data.
This CGS-to-SI converter handles ten key physical quantities: force (dyne ↔ newton), energy (erg ↔ joule), pressure (barye ↔ pascal), dynamic viscosity (poise ↔ pascal-second), kinematic viscosity (stokes ↔ m²/s), magnetic flux density (gauss ↔ tesla), magnetic flux (maxwell ↔ weber), magnetic field strength (oersted ↔ A/m), luminance (stilb ↔ cd/m²), and acceleration (gal ↔ m/s²).
Select the physical quantity, choose the direction, enter a value, and get the conversion instantly. The tool includes a complete reference table of all CGS-SI factors, quick preset buttons, and scientific notation outputs for very large or very small values commonly encountered in physics.
CGS units appear frequently in astrophysics, materials science, and older engineering references. Manually recalling conversion factors like 1 dyne = 10⁻⁵ N or 1 gauss = 10⁻⁴ T is time-consuming and error-prone. This converter provides instant, accurate bidirectional conversion for the ten most important CGS-SI quantity pairs used in practical academic and industrial workflows.
Each CGS unit relates to its SI counterpart by a power-of-ten factor: 1 dyn = 10⁻⁵ N 1 erg = 10⁻⁷ J 1 Ba = 0.1 Pa 1 P = 0.1 Pa·s 1 St = 10⁻⁴ m²/s 1 G = 10⁻⁴ T 1 Mx = 10⁻⁸ Wb 1 Oe ≈ 79.5775 A/m 1 sb = 10⁴ cd/m² 1 Gal = 10⁻² m/s²
Result: 1 N
100,000 dynes equals 1 newton. Since 1 dyne = 10⁻⁵ N, multiplying 100,000 × 10⁻⁵ = 1 N. This is consistent with F = ma: 1 kg × 1 m/s² = 1 N = 1000 g × 100 cm/s² in CGS = 10⁵ dyn.
The CGS system was introduced by the British Association for the Advancement of Science in 1874. It became the standard in physics and engineering until the mid-20th century when the MKS (metre-kilogram-second) system, later formalized as SI, gained dominance. The transition was formalized in 1960 when the General Conference on Weights and Measures adopted SI.
Three variants exist for electromagnetic quantities: CGS-ESU (electrostatic units), CGS-EMU (electromagnetic units), and CGS-Gaussian (a hybrid). Each defines charge, current, and field differently, leading to different conversion factors to SI. The Gaussian system is most common in theoretical physics.
Astrophysics journals (e.g., ApJ, MNRAS) commonly use CGS. Gravitational acceleration is measured in gals in geodesy. Material hardness testers report in CGS-derived units. Understanding both systems and converting between them is a practical necessity for researchers working across disciplines.
The CGS (centimetre-gram-second) system defines base units as the centimetre for length, gram for mass, and second for time. Derived units like dyne, erg, and poise follow from these base units.
Astrophysics, plasma physics, and some materials science journals use CGS because the Gaussian CGS electromagnetic equations are simpler (no ε₀ or µ₀ constants). Legacy literature also keeps CGS relevant.
Multiply by 10⁻⁴. So 1 gauss = 0.0001 tesla, or equivalently 10,000 gauss = 1 tesla.
A dyne is the CGS unit of force. It is the force needed to accelerate 1 gram at 1 cm/s². One newton equals 100,000 dynes.
One erg = 10⁻⁷ joules, so 1 joule = 10,000,000 ergs. The erg is very small — roughly the energy of a grain of sand falling 1 cm.
Poise measures dynamic viscosity. Water at 20°C has a viscosity of about 1 centipoise (0.01 poise). Honey is approximately 2,000–10,000 centipoise depending on type and temperature.