About the t to mg calculation
One tonne is exactly 1,000,000,000 milligrams, so converting between them is a single multiplication. Enter any value above and the result updates as you type. A metric tonne is exactly 1,000 kg — not the same as a US or imperial ton. The usual unit for medication doses and nutrient quantities.
Formula
mg = t × 1,000,000,000
1 t = 1,000,000,000 mg
1 mg = 1.0000e-9 tWorked example
To convert 1 t, multiply by 1,000,000,000: 1 × 1,000,000,000 = 1,000,000,000 mg.
Frequently asked questions
How many milligrams are in a tonne?
There are 1,000,000,000 milligrams in one tonne. To convert any amount, multiply the number of tonnes by 1,000,000,000.
How do I convert milligrams back to tonnes?
Divide instead of multiplying, or equivalently multiply by 1.0000e-9. One milligram is 1.0000e-9 tonnes.
Is this conversion exact?
Yes. Since the international agreement of 1959, the relationship between tonnes and milligrams is defined exactly rather than measured, so the only rounding here is in how many decimal places we show.
Where is each of these units used?
Tonnes: a metric tonne is exactly 1,000 kg — not the same as a US or imperial ton. Milligrams: the usual unit for medication doses and nutrient quantities.
Sources
- NIST Special Publication 811 — Guide for the Use of the International System of Units