Mass • NIST Exact

Stones Kilograms

st → kg

1 st = 6.35029318 kgNIST Exact

st → kg Reference Table

st kg
0.01 st 0.0635029318 kg
0.1 st 0.635029318 kg
0.5 st 3.17514659 kg
1 st 6.35029318 kg
2 st 12.70058636 kg
5 st 31.7514659 kg
10 st 63.5029318 kg
20 st 127.0058636 kg
50 st 317.514659 kg
100 st 635.029318 kg
500 st 3175.14659 kg
1000 st 6350.29318 kg

Values based on NIST SP 811 conversion factors

🌍 Real-World Examples

10 stone (healthy weight benchmark UK)

10 st = 63.5029318 kg

12 stone (average UK male)

12 st = 76.20351816 kg

9 stone (petite adult weight)

9 st = 57.15263862 kg

Why Convert Stones to Kilograms?

Converting between stones (st) and kilograms (kg) is one of the most common mass conversions. Whether for engineering, cooking, travel, or science, knowing how to quickly convert st to kg saves time and prevents errors.

Mass conversions between st and kg come up constantly in everyday life. International travelers need to convert luggage weight limits — airlines typically allow 23 kg (≈50.7 lb) for checked bags and 7-10 kg for carry-on. In fitness, gym equipment in the US uses pounds while most of the world uses kilograms. Cooking recipes from different countries require converting between grams, ounces, and pounds for accurate measurements.

How to Convert Stones to Kilograms

To convert stones to kilograms, use the following formula:

kg = st × 6.35029318

Example: 1 st = 6.35029318 kg

For example, 5 st = 31.7514659 kg, 10 st = 63.5029318 kg, and 100 st = 635.029318 kg. Our calculator above performs this conversion instantly with full precision — no rounding errors.

Common Use Cases

  • 10 stone (healthy weight benchmark UK): 10 st = 63.5029318 kg
  • 12 stone (average UK male): 12 st = 76.20351816 kg
  • 9 stone (petite adult weight): 9 st = 57.15263862 kg

Common Mistakes to Avoid

  • Confusing mass and weight: In everyday use, "weight" and "mass" are interchangeable, but in science they differ. This converter handles mass units.
  • Pound ambiguity: The avoirdupois pound (lb, used for everyday weight) differs from the troy pound (used for precious metals). This converter uses avoirdupois.
  • Rounding errors in cooking: When converting st to kg for recipes, round to the nearest practical measurement (e.g., nearest 5g or ¼ oz).

Pro Tips

  • Memorize the factor: 1 st = 6.35029318 kg. For quick mental math, remember this base conversion.
  • Quick reference: 5 st = 31.7514659 kg · 10 st = 63.5029318 kg · 25 st = 158.7573295 kg · 50 st = 317.514659 kg · 100 st = 635.029318 kg
  • Bookmark this page: Save this converter for instant access. It works offline once loaded — no internet needed.

Stones to Kilograms Conversion Table

stkg
0.01 st0.0635029318 kg
0.1 st0.635029318 kg
0.5 st3.17514659 kg
1 st6.35029318 kg
2 st12.70058636 kg
5 st31.7514659 kg
10 st63.5029318 kg
20 st127.0058636 kg
50 st317.514659 kg
100 st635.029318 kg
500 st3175.14659 kg
1000 st6350.29318 kg

All values in this table are mathematically exact per NIST SP 811.

Frequently Asked Questions

How many kilograms are in 1 stone?

1 st equals 6.35029318 kg. This is an exact conversion factor defined by NIST.

How do I convert stones to kilograms?

Multiply the value in st by the conversion factor. For example, 10 st = 63.5029318 kg. Use our calculator above for instant results.

Is the stones to kilograms conversion exact?

Yes, this conversion is mathematically exact based on the international definition of these units (NIST SP 811).

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