What is tonne?
A tonne, also known as a metric ton, is a unit of mass equal to 1,000 kilograms. It is used in industrial shipping, cargo measurement, and large-scale material production and trade.
Real-world uses
Tonnes (metric tons) are used globally for cargo shipping weights, industrial raw materials, agricultural harvest yields, and carbon emissions reporting. A standard shipping container might carry up to about 28 tonnes of cargo.
History
The tonne derives from the Old French "tonne" meaning a large cask. It was formalized in the metric system as exactly 1,000 kilograms. Though not an official SI unit, it is accepted for use with SI and is the global standard in trade.
Common mistakes
Confusing the metric tonne (1,000 kg) with the US short ton (907.18 kg) or the Imperial long ton (1,016.05 kg). Using "ton" ambiguously without specifying which system creates significant commercial errors.
What is gram?
A gram is a metric unit of mass equal to one thousandth of a kilogram. It is widely used in cooking, food labelling, and the measurement of small quantities in science and pharmacy.
Real-world uses
Grams are used for food nutrition labelling, postal weight limits, cooking recipes (especially in baking where precision matters), and jewellery weights. Pharmacists measure drug dosages in grams and fractions thereof.
History
The gram was the original base unit of mass in the French metric system of 1795, defined as the mass of one cubic centimetre of water. It later became the base unit in the CGS system before the kilogram took precedence in SI.
Common mistakes
Confusing grams with grains (1 grain ≈ 0.065 g), a common error in pharmaceutical contexts. Also, mistaking "g" for "G" in digital contexts where G means giga.
When is this conversion used?
Cooking recipes and food packaging often switch between grams and ounces, especially when adapting recipes from different culinary traditions.
Worked examples
1 tonne = 1,000,000 gram
1 gram = 0.001 kilogram
How to convert tonne to gram
To convert tonne to gram, multiply the value by 1,000,000.
To convert gram back to tonne, multiply by 0.000001.
Measurement standards
The kilogram is defined by fixing the Planck constant to exactly 6.62607015 × 10⁻³⁴ joule-seconds, as established at the 26th General Conference on Weights and Measures in 2018. This ended the last SI definition based on a physical artefact.
Did you know?
The International Prototype of the Kilogram, a platinum-iridium cylinder stored near Paris since 1889, was found to have drifted by about 50 micrograms relative to its copies over a century — roughly the mass of a fingerprint.
Quick reference: tonne to gram
| tonne | gram |
|---|---|
| 0.1 | 100,000 |
| 0.5 | 500,000 |
| 1 | 1,000,000 |
| 2 | 2,000,000 |
| 5 | 5,000,000 |
| 10 | 10,000,000 |
| 25 | 25,000,000 |
| 50 | 50,000,000 |
| 100 | 100,000,000 |
| 250 | 250,000,000 |
| 500 | 500,000,000 |
| 1,000 | 1.000000e+09 |
Common values
| tonne | gram | |
|---|---|---|
| A paperclip | 0.001 tonne | 1,000 gram |
| A smartphone | 0.175 tonne | 175,000 gram |
| A bag of sugar | 0.001 tonne | 1,000 gram |
| Average adult human | 0.07 tonne | 70,000 gram |
| A small car | 1.2 tonne | 1,200,000 gram |