Magnetic Field Strength Converter – Tesla to Gauss & µT in 3 Easy Steps
Magnetic Field Converter
Use this magnetic field strength converter: type a value into any unit field to instantly convert tesla, gauss, mT and µT.
Use this free magnetic field strength converter to switch between tesla (T), gauss (G), millitesla (mT) and microtesla (µT). Type a value in any box and the other units update instantly, so converting tesla to gauss, or gauss to microtesla, takes no mental maths.
Quick answer
1 tesla = 10,000 gauss = 1,000 millitesla = 1,000,000 microtesla, and 1 gauss = 100 microtesla = 0.0001 tesla. To convert tesla to gauss, multiply by 10,000. To convert gauss to microtesla, multiply by 100. For example, a 1.5 T MRI scanner is 15,000 G, and Earth’s field of about 0.5 G is 50 µT.
Table of Contents
Magnet suppliers, physics textbooks, MRI specifications and phone sensor apps all describe magnetic fields, but in different units. Older and US sources often use gauss, while modern science and engineering use the SI unit, the tesla. Mixing them up by a factor of 10,000 is easy.
This magnetic field strength converter keeps all four units side by side, with a reference matrix for quick checks. It works in your browser.
What Do Tesla and Gauss Measure?
Tesla and gauss measure magnetic flux density, usually written B. It describes how strong a magnetic field is at a point, in terms of the force it exerts on moving charges and magnetic materials. The tesla is the SI unit. The gauss belongs to the older CGS system and is still common in magnet catalogues and gaussmeters.
Strictly speaking, "magnetic field strength" in physics often refers to H, measured in amperes per metre or oersted. In everyday use, people say field strength when they mean flux density, which is what this converter handles.
Magnetic Field Unit Conversion Formulas
- Tesla to gauss: G = T × 10,000
- Gauss to tesla: T = G ÷ 10,000
- Tesla to millitesla: mT = T × 1,000
- Gauss to microtesla: µT = G × 100
- Millitesla to gauss: G = mT × 10
Typical Magnetic Field Strengths
| Source | Tesla | Gauss | Microtesla |
|---|---|---|---|
| Earth’s magnetic field | 0.000025 to 0.000065 | 0.25 to 0.65 | 25 to 65 |
| Fridge magnet (approx.) | 0.005 | 50 | 5,000 |
| Strong neodymium magnet (surface) | about 1 | about 10,000 | about 1,000,000 |
| Hospital MRI scanner | 1.5 or 3 | 15,000 or 30,000 | 1.5 to 3 million |
Figures for magnets are approximate and depend on size, shape and distance from the surface.
How to Use the Magnetic Field Strength Converter
Step 1: Enter a Value in Tesla
Type a value in the Tesla box. A 1.5 T MRI field converts to 15,000 gauss, 1,500 millitesla and 1,500,000 microtesla.
Step 2: Convert Gauss to Microtesla
Start from any field. Typing 0.5 in Gauss, a typical value for Earth’s field, shows 0.00005 T, 0.05 mT and 50 µT, the unit most phone sensor apps use.
Step 3: Check the Reference Matrix
The matrix under the fields lists the key relationships: 1 T = 10,000 G, 1 T = 10⁶ µT, 1 G = 100 µT and 1 G = 0.0001 T. Press Clear Fields to start again.
Where You Will See These Units
- Magnet shopping: suppliers often quote surface field in gauss and pull force in kilograms or pounds.
- Medical imaging: MRI scanners are rated in tesla, usually 1.5 T or 3 T.
- Phones and compasses: built-in magnetometers report values in microtesla.
- Physics and engineering: motor, transformer and sensor design uses tesla and millitesla.
- Geophysics: Earth’s field and magnetic surveys are often reported in nanotesla or microtesla.
Tips for Accurate Conversions
- Check whether a datasheet gives flux density (T, G) or field strength H (A/m, Oe) before converting.
- Note the distance from the magnet surface, since field strength drops quickly with distance.
- For very small fields, use microtesla or nanotesla to avoid long strings of zeros.
Need other physics conversions? Try the Radiation Converter or the Luminance Unit Converter.
Frequently Asked Questions
How many gauss are in a tesla?
There are exactly 10,000 gauss in 1 tesla.
How do I convert gauss to tesla?
Divide by 10,000. For example, 5,000 G is 0.5 T.
How strong is Earth’s magnetic field?
About 25 to 65 microtesla, or 0.25 to 0.65 gauss, depending on location.
What is the difference between tesla and gauss?
Both measure magnetic flux density. Tesla is the SI unit; gauss is the older CGS unit. One tesla equals 10,000 gauss.
Is a 3 T MRI stronger than a fridge magnet?
Much stronger. A 3 T MRI is about 30,000 gauss, while a typical fridge magnet is around 50 gauss.
Is my data saved?
No. The magnetic field strength converter runs entirely in your browser.