How this conversion works
Magnetic flux density, often just called magnetic field strength in everyday use, has the SI unit tesla. The CGS unit is the gauss, exactly 10⁻⁴ T.
So 1 T = 10,000 G and 1 µT = 0.01 G.
Formula: result = value × (base units per source unit) ÷ (base units per target unit)
Where this conversion is used
- Magnet and sensor specifications in gauss or millitesla.
- MRI field strengths in tesla.
- Magnetometer and compass readings of Earth's field in µT or nT.
Worked example: Earth's field of about 50 µT in gauss
- 1 µT = 0.01 G.
- 50 × 0.01 = 0.5 G.
Unit definitions
| Unit | In teslas | Note |
|---|---|---|
| Tesla (T) | 1 | |
| Millitesla (mT) | 0.001 | |
| Microtesla (µT) | 0.000001 | |
| Nanotesla (nT) | 1e-9 | |
| Gauss (G) | 0.0001 | CGS unit: 10⁻⁴ T exactly. |
| Milligauss (mG) | 1e-7 | |
| Gamma (γ) | 1e-9 | 1 nT, used in geophysics. |
Teslas to gauss
| Tesla (T) | Gauss (G) |
|---|---|
| 0.0001 | 1 |
| 0.001 | 10 |
| 0.01 | 100 |
| 0.1 | 1,000 |
| 1 | 10,000 |
| 1.5 | 15,000 |
| 3 | 30,000 |
Microteslas to gauss
| Microtesla (µT) | Gauss (G) |
|---|---|
| 1 | 0.01 |
| 25 | 0.25 |
| 50 | 0.5 |
| 65 | 0.65 |
| 100 | 1 |
Things to watch for
- Magnetic field strength H (A/m, oersted) is a different quantity and is not converted here.
Precision and sources
Results are calculated from the definitions above and rounded to 12 significant digits; the converter shows up to eight decimal places and the tables four. Reference: NIST Special Publication 811, Guide for the Use of the International System of Units, Appendix B.
Frequently asked questions
How strong is an MRI magnet?
Clinical MRI scanners commonly use 1.5 T or 3 T, which is 15,000 G or 30,000 G.