Milligrams to Stone Converter

Converting milligrams to stone is a multiplication by a fixed factor: 1 mg = 1.5747e-7 st. The table below covers the values people look up most often, and the formula section shows exactly where that factor comes from.

Because one milligram works out to 1.5747e-7 st, the stone is the far smaller unit of the two: a figure given in stone always carries a smaller number than the same measurement in milligram. A chart drawn in mg can hide that, so check which label the axis uses before you compare two readings.

Where a legal or postal limit is set in stone, the same limit expressed in milligrams has to be exact — an overshoot of even one unit can change the chargeable band.

The conversion factor used here is 1.5747e-7 st per milligram (7 significant digits as shown). Kept to seven figures it covers professional measurement; if you round it to two or three decimals for a spreadsheet, the error scales with the input — at a value of 1,000 mg a factor rounded to three decimals can be off by a measurable amount. The reverse direction uses 6350293 mg per st, the exact reciprocal, so a round trip through both pages returns your original number.

Milligrams to Stone formula

Use this formula to convert any milligram value to stone:

st = mg × 1.5747e-7

Worked example: 100 mg × 1.5747e-7 = 1.5747e-5 st.

Milligrams to Stone conversion table

Milligrams (mg)Stone (st)
0.5 mg7.8737e-8 st
1 mg1.5747e-7 st
2 mg3.1495e-7 st
5 mg7.8737e-7 st
10 mg1.5747e-6 st
20 mg3.1495e-6 st
50 mg7.8737e-6 st
100 mg1.5747e-5 st
500 mg7.8737e-5 st
1000 mg0.000157473 st

How to convert milligrams to stone

Multiply the milligram value by 1.5747e-7 to get the equivalent in stone. This single factor works for every value in the table above and for anything else you need — there is no per-value adjustment, which is why a conversion table and a calculator always agree.

If you need the opposite direction, use the Stone to Milligrams converter instead of dividing by hand; both pages use the same source factors. For every other mg conversion in one place, see the mg conversion hub.

Frequently asked questions

How many stone are in 1 milligram?
1 milligram = 1.5747e-7 st.

What is 100 milligrams in stone?
100 mg = 1.5747e-5 st.

Is converting milligrams to stone the same as stone to milligrams?
No — the direction changes the multiplier. The reverse conversion (1 st = 6350293 mg) is on the Stone to Milligrams page.

Related conversions

Try the ConvBolt Unit Converter for any other weight unit, browse the Weight conversions, or read our conversion guides.