Kilograms to Tonnes
Convert kilograms to tonnes instantly — one kilogram is 0.001 tonnes.
| Kilograms | Tonnes |
|---|---|
| 1 kg | 0.001 t |
| 2 kg | 0.002 t |
| 3 kg | 0.003 t |
| 5 kg | 0.005 t |
| 10 kg | 0.01 t |
| 25 kg | 0.025 t |
| 50 kg | 0.05 t |
| 100 kg | 0.1 t |
How to use
- Enter a value in the Kilograms field.
- The Tonnes figure appears immediately — no button to press.
- Typing in the Tonnes field converts back to Kilograms the same way.
- Use the reference table for the values that come up most often.
Kilograms to Tonnes formula
The factor from kilograms to tonnes is 0.001.
t = kg × 0.001
Put another way, one kilogram is exactly 1/1,000 of a tonne.
Why this factor: the kilogram and the tonne are both defined against the kilogram, so dividing one definition by the other gives 0.001 directly. Both definitions are set out in full below.
To go the other way, divide by 0.001 — or use the Tonnes to Kilograms converter, which is the same calculation reversed.
Worked example
Take 2 kg and multiply by the factor 0.001: the result is 0.002 t.
2 kg × 0.001 = 0.002 t
The converter above does this for any value you type, in either direction.
What is a kilogram?
The kilogram is the SI base unit of mass — the reference for every other mass unit.
Definition: Since 2019 the kilogram has been defined by fixing the Planck constant at exactly 6.62607015×10⁻³⁴ joule-seconds, retiring the physical platinum-iridium cylinder that defined it for 130 years.
Where it is used: Universal in science, trade and everyday weighing outside the United States.
What is a tonne?
A tonne, or metric ton, is 1,000 kilograms — the standard unit for bulk freight and industrial quantities.
Definition: Exactly 1,000 kilograms. Accepted for use with SI but not itself an SI unit.
Where it is used: Shipping and freight, steel and cement output, vehicle masses, and carbon emissions accounting.
Worth knowing: Distinct from the US short ton (2,000 lb ≈ 907 kg) and the UK long ton (2,240 lb ≈ 1,016 kg).
Kilograms vs Tonnes
The kilogram is an SI unit while the tonne is a metric unit. That is why the factor between them is not a round number: the two systems were defined independently and only later tied together by exact agreement.
Frequently asked questions
How many tonnes are in a kilogram?
One kilogram equals 0.001 tonnes.
What is the formula to convert kilograms to tonnes?
Multiply the number of kilograms by 0.001. To reverse it, divide by 0.001 instead.
How do I convert tonnes back to kilograms?
Divide by 0.001, which is the same as multiplying by 1000.
How many tonnes are in 10 kilograms?
10 kg works out to 0.01 t.
Is there anything to watch out for with tonnes?
Distinct from the US short ton (2,000 lb ≈ 907 kg) and the UK long ton (2,240 lb ≈ 1,016 kg).
How is the kilogram defined?
Since 2019 the kilogram has been defined by fixing the Planck constant at exactly 6.62607015×10⁻³⁴ joule-seconds, retiring the physical platinum-iridium cylinder that defined it for 130 years.