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Convert Grains to Grams

1 grain is 0.06 g. One grain is exactly 0.06479891 grams.

One grain is 0.06479891 grams. To convert grains to grams, multiply by 0.06479891; to go the other way, divide by 0.06479891 or multiply by 15.432358. The factor is exact rather than rounded: it follows from NIST Handbook 44. Exactly 64.79891 milligrams, the unit both the avoirdupois and troy systems are built from.

Factor checked against the defining standard · How we check

Grams
0.06 g
Grains × 0.06479891
1 * 0.06479890.065 g

1 grain in every weight unit

1 grain expressed in every weight unit
UnitValueExact factor
ounces0.002285714286 oz× 0.00228571428571
pounds0.0001428571429 lb× 0.000142857142857
stone0.00001020408163 st× 0.0000102040816327
US tons0.00000007142857143 ton× 0.0000000714285714286
micrograms64,798.91 mcg× 64,798.91
milligrams64.79891 mg× 64.79891
centigrams6.479891 cg× 6.479891
grams0.06479891 g× 0.06479891
kilograms0.00006479891 kg× 0.00006479891
slugs0.000004440135739 slug× 0.0000044401357388
tonnes0.00000006479891 t× 0.00000006479891
carats0.32399455 ct× 0.32399455
troy ounces0.002083333333 ozt× 0.00208333333333
grains (as entered)1 gr—
long tons0.0000000637755102 LT× 0.0000000637755102041

Factors are entered by hand from NIST Handbook 44 rather than derived from a units library, so the ones that terminate are exact rather than rounded.

How do you convert grains to grams? The converter and the working

  1. 1.Take the measurement in grains.
  2. 2.Multiply by 0.06479891 — that is how many grams fit in one grain.
  3. 3.To go back the other way, divide by 0.06479891, or multiply by 15.432358.

Worked example: 25 grains to grams

Formula
gr × 0.06479891 = g
Arithmetic
25 × 0.06479891 = 1.62 g
Answer
25 gr = 1.62 g

The factor is exact, so this figure is exact too — only the display is rounded.

Grains to grams conversion table

Grains to grams conversion table
GrainsGrams
1 gr0.06 g
2 gr0.13 g
3 gr0.19 g
4 gr0.26 g
5 gr0.32 g
6 gr0.39 g
7 gr0.45 g
8 gr0.52 g
9 gr0.58 g
10 gr0.65 g
12 gr0.78 g
15 gr0.97 g
20 gr1.3 g
25 gr1.62 g
50 gr3.24 g
100 gr6.48 g
200 gr12.96 g
300 gr19.44 g
500 gr32.4 g
1000 gr64.8 g
2000 gr129.6 g
5000 gr323.99 g
10000 gr647.99 g

What is a grain?

Exactly 64.79891 milligrams, the unit both the avoirdupois and troy systems are built from. Bullet weights and powder charges are still measured in it, and so are some pharmaceutical doses.

What is a gram?

One thousandth of a kilogram, and the unit nutrition labels use worldwide.

How many grams are in a grain?

One grain is 0.06479891 grams, exactly. Going the other way, one gram is 15.432358 grains. Both figures come from the same defined relation rather than from a measurement, which is why they are the same today as they were in 1959.

Every weight unit here

The whole group — 15 units with their symbols and the size of each one in kilograms — is on the conversion index, along with every pair it makes. The table above already gives each of them relative to a grain.

Source: NIST Handbook 44 — mass and weight

Cite this page

APA
Rule Calculator. (2026). Convert Grains to grams. Rule Calculator. https://rulecalculators.com/convert/grain-to-gram
MLA
"Convert Grains to grams." Rule Calculator, August 16, 2026, https://rulecalculators.com/convert/grain-to-gram.
Chicago
Rule Calculator. "Convert Grains to grams." Rule Calculator. Last reviewed August 16, 2026. https://rulecalculators.com/convert/grain-to-gram.

The date is when the figures on this page were last checked against their source, not the day you opened it. Add your own access date if your style needs one.

Questions people actually ask

How many grams are in a grain?
0.06479891. One thousandth of a kilogram, and the unit nutrition labels use worldwide.
How do I convert grams back to grains?
Divide by 0.06479891, or multiply by 15.432358 — they are the same operation.

Other weight conversions

Grams to grains — the same conversion the other way.

Calculators that work in weight