Convert Stones (st) to Tonnes (t)
1 stone equals 0.00635029 tonnes.
Formula:
t = st × 0.00635029
Stone to Tonne Converter
Enter a numeric value or fraction to convert
Result
Sig. Figures:
Recent Conversions
How to Convert Stone to Tonne
1 stone = 0.00635029 tonnes
Tonne = Stone × 0.00635029
Example: 1 st × 0.00635029 = 0.00635029 t
Reverse Conversion
To convert tonnes back to stones:
- Remember, 1 tonne equals 157.473 stones.
- To convert 0.00635029 t to st, multiply
0.00635029 x 157.473, resulting in1 st.
Common Stone to Tonne Conversions
| Stone | Tonne | Actions |
|---|---|---|
| 50 stones | 0.317515 tonnes | |
| 100 stones | 0.635029 tonnes | |
| 500 stones | 3.17515 tonnes | |
| 1000 stones | 6.35029 tonnes |
Stones to tonnes Conversion Table
Reference table with common stones to tonnes conversions. All values calculated with high precision.
Stones to Tonnes Table
1000 to 1 × 108
Tonnes to Stones Table
1 to 100000
Definition of Stone
- Definition
- The stone (st) is a traditional British unit of mass, primarily used for expressing human body weight in the UK and Ireland.
Although not part of the SI system, it remains culturally relevant and widely understood in health-related contexts. - Exact factor
- 1 st = 14 lb = 6.35029318 kg
- Examples
- • 11 st ≈ 69.85 kg
• 12 st 7 lb ≈ 79.38 kg
Definition of Tonne
- Definition
- The tonne (t), also called the metric ton, is a metric unit of mass equal to one thousand kilograms. It is commonly used in industry, shipping, and science.
The tonne provides a convenient scale for large masses while remaining compatible with the SI system. - Exact factor
- 1 t = 1000 kg = 2204.6226218 lb
- Examples
- • 1.5 t = 1500 kg
• 2 t ≈ 4409.25 lb
About the Stone
Facts & Uses
- Traditional British and Irish unit equal to exactly 14 avoirdupois pounds = 6.35029318 kg. Still in everyday use in the UK and Ireland for body weight.
- Used in healthcare records, weight-loss programs, and sports broadcasting (boxing, rugby, horse racing) — typically reported as "X stone Y pounds" (e.g., 12 st 7 lb).
- Largely obsolete in commerce — UK retail and food packaging have used metric units (kg) since the 1995/2000 EU directives — but persists culturally for personal weight.
- Not used in the United States or in continental Europe; American expatriates in the UK often find the unit confusing on their first GP visit.
Curiosities
- The name comes literally from the practice of using stones as standard weights in medieval markets. The value varied wildly by region and commodity — from 4 lb (in some wool trades) to 32 lb (for cheese in Northumberland) — until the 1835 Weights and Measures Act fixed it at 14 lb.
- A typical adult man in the UK weighs around 11–14 stone (70–89 kg); a typical woman 9–12 stone (57–76 kg).
- The plural is irregular: "He weighs 12 stone" (singular form even for plural quantity) — a quirk of British English.
- 1 st = 14 lb = exactly 6.35029318 kg ≈ 224 oz.
Sources
About the Tonne
Facts & Uses
- Also called the metric ton, equal to exactly 1000 kilograms. Recognized as a non-SI unit accepted for use with the SI by the BIPM.
- Standard for industrial production (steel, cement, grain harvests), international shipping (cargo manifests, container weights), and environmental reporting (CO₂ emissions in tonnes).
- Used in vehicle weight ratings (a small car ≈ 1–1.5 t; a fully loaded semi-truck ≈ 40 t in the EU), mining, and agriculture.
- Distinct from the US short ton (2000 lb ≈ 907 kg) and the UK long ton (2240 lb ≈ 1016 kg) — confusion between the three is a common source of trade disputes.
Curiosities
- The international symbol is "t" (lowercase) — the uppercase T is reserved for the tesla (magnetic flux density), an entirely unrelated SI unit.
- Global annual CO₂ emissions are measured in billions of tonnes (Gt); a single transatlantic flight emits about 1 t of CO₂ per passenger.
- The blue whale, the largest animal ever known, weighs up to 180 tonnes — equivalent to about 30 African elephants.
- 1 t = exactly 1000 kg = 2204.62 lb ≈ 1.102 short tons ≈ 0.984 long tons.
Sources
Frequently Asked Questions
How many tonnes are in one stone?
One stone equals 0.00635029 tonnes. To convert, multiply the stone value by 0.00635029. For the reverse, divide the tonne value by 0.00635029 (or multiply by 157.473).
What is 0.04 stones in tonnes?
0.04 stones = 0.00025401 tonnes. This is one of the most commonly searched conversions for this pair.
How precise is the stone-to-tonne conversion?
The factor 0.00635029 is accurate to 6 significant figures, derived from international measurement standards. Our calculator uses full precision internally.
Looking for the reverse? Convert Tonne to Stone
Related Weight (Mass) Converters
Explore other weight (mass) conversion tools:
Need a combined format?
- Kg to Stones and Pounds — UK body weight format
Related in other categories:
- G-force to m/s² — Force = mass × acceleration (F = ma)
Conversion factors verified against NIST (National Institute of Standards and Technology), BIPM (International Bureau of Weights and Measures)
1 lb = 0.45359237 kg by international agreement (1959).
Last reviewed: March 2026
