⚖️ Comparison · Updated for 2026
Stones vs Kilograms
Side-by-side comparison, when-to-use-each guide, and instant conversion. Reviewed for 2026.
Quick answer: 1 stone = 14 lbs = 6.35029 kg. The stone is uniquely British — still standard for body weight in the UK and Ireland. NHS records, gym apps, and bathroom scales default to stones, often as 'st lb' (e.g. 11st 4lb = 71.6 kg).
Decision guide — when to use which
Use Stones when…
UK and Ireland body weight (universally), some Commonwealth horse-racing.
Use Kilograms when…
Body weight everywhere outside UK/Ireland, all sports above amateur level, medical context worldwide (including the NHS for clinical work).
📊 Side-by-side comparison
| Aspect | Stones | Kilograms |
|---|---|---|
| Unit size | 14 lbs / 6.35 kg | SI base unit |
| UK everyday use | Body weight only | Increasingly common, especially in gyms |
| UK NHS use | Patient self-reported | Clinical and prescription dosing |
| Conversion | ×6.35029 → kg | ×0.157473 → stones |
Frequently asked
?
How heavy is 12 stone in kg?
12 stone = 76.2 kg exactly (12 × 6.35029 kg). Common stone-to-kg values: 10st = 63.5 kg, 11st = 69.85 kg, 12st = 76.2 kg, 13st = 82.55 kg, 14st = 88.9 kg. NHS healthy weight range for most adults: approximately 8–13 stone (50–82 kg).
?
Do UK doctors use stones?
NHS clinical records use kg for prescribing and clinical decisions, but doctors will often discuss weight in stones because that's what patients understand.
Reviewed for 2026. All conversion factors and historical references verified against official sources (ISO standards, government weights & measures legislation, IEC technical specifications). Built by a UK-based qualified primary teacher and FA Level 2 coach as part of 247QuickTools' free utility-tools project. We don't sell SEO links or accept paid placements in this content.