Stone to Grams Converter

Stone to Grams

Convert stone (st) to grams (g). Both measure mass and weight, and the conversion comes up in cooking, shipping, fitness work.

The Formula

`` grams = stone × 6350.29318 stone = grams × 0.000157473044418 `

One stone is 6,350.29 grams, and one gram is 1.5747e-4 stone.

Conversion Table

Stone	Grams
1 st	6,350.29 g
2 st	12,700.59 g
5 st	31,751.47 g
10 st	63,502.93 g
25 st	158,757.33 g
50 st	317,514.66 g
100 st	635,029.32 g
500 st	3,175,146.59 g
1,000 st	6,350,293.18 g

The Other Direction

Grams	Stone
1 g	1.5747e-4 st
2 g	3.1495e-4 st
5 g	7.8737e-4 st
10 g	0.001575 st
25 g	0.003937 st
50 g	0.007874 st
100 g	0.015747 st
500 g	0.078737 st
1,000 g	0.157473 st

What Each Unit Is

Stone (st) — exactly 14 pounds, or 6.35029318 kilograms. A medieval trade weight that varied by commodity until standardised at 14 lb in 1835.

Grams (g) — one thousandth of a kilogram. The metric unit for small masses; cooking, nutrition and postage all work in grams.

A Sense of Scale

• British body weight is often given in stone and pounds
• An adult is typically 9–14 stone
• A paperclip is about 1 g
• A sheet of A4 is 5 g
• A tennis ball is 58 g

Precision

The factor 6350.29318 is rounded. For engineering work carry more digits than the table above, and round only at the end — rounding at each step compounds.

Watch Out For

• Effectively British-only. US sources give body weight in pounds alone.

In Code

`javascript const stoneToGram = (value) => value * 6350.29318; ``

Where This Conversion Comes Up

• Cooking
• Shipping
• Fitness
• Medicine
• Manufacturing

How Many Decimals Do You Need?

Rounding the factor costs accuracy, and how much depends on the factor. Converting 137 st with the factor truncated at each decimal place:

Decimals kept	Factor	137 st becomes	Error
0	6350	869,950	0.0046%
1	6350.3	869,991.1	0.0001%
2	6350.29	869,989.73	—
3	6350.293	869,990.14	—
4	6350.2932	869,990.17	—

A rule that holds for any conversion: round once, at the end. Rounding the factor and then multiplying compounds the error through every subsequent calculation, while carrying full precision and rounding the final answer does not.

The right number of significant figures is set by your input, not by the converter. If you measured stone to three significant figures, the answer in grams is only good to three — writing more digits claims precision the measurement never had.