Convert Millitesla to Nanotesla (mT to nT)

Formula

nT = mT × 1000000

Derivation from SI units:

• 1 mT = 10⁻³ T
• 1 nT = 10⁻⁹ T (also called a gamma in geophysics)
• 1 mT = 0.001 T ÷ 1 × 10⁻⁹ T per nT = 1000000 nT

Both units are defined exactly, so the factor is exact. Millitesla definition: millitesla; Nanotesla definition: nanotesla.

Worked examples

1. A reading of 5 mT converts to 5000000 nT.
   5 mT × 1000000 = 5000000 nT
2. A value of 100 mT is 100000000 nT.
   100 mT × 1000000 = 100000000 nT

Where it's used

Millitesla are used for fridge and small permanent magnets (about 5–100 mT), while nanotesla appear in geomagnetic surveys and magnetometers. Both measure magnetic flux density (B field), so the conversion is a fixed factor.

Millitesla to other magnetic flux density units

Frequently asked questions

Sources

• The International System of Units (SI), 9th edition (SI Brochure), Bureau International des Poids et Mesures .

Last reviewed: 2026-10-15. Factors are stored exactly and computed with 50-digit decimal arithmetic. See how we verify conversion factors.