# Articles > How big is one billion?

*by Alexis Ulrich*

Big numbers make our head spin. The more zeros we add, the less understandable they are. Ten thousand, a hundred thousand, these are numbers that we can more or less understand. One million is already more difficult. Beyond that, the factors of scale are so enormous that it is hard to wrap our heads around such quantities. So, in the end, how much is a billion?

## One billion grains of rice

There are about 40,000 grains of rice in 1 kilo of rice (depending on the grains in question, this is a mere approximation). One million grains of rice represents about 25 kg of rice.

To get to a billion, we multiply by a thousand: a billion grains of rice weighs 25,000 kg of rice, or 25 tons, for a volume of 30 m^{3}.

## One billion litres of water

A 25-metre-long swimming pool contains approximately 700,000 litres of water, or 700,000 litres. One million litres of water is equivalent to about one and a half swimming pools.

To get to the billion, we need to change pools. A 50-metre Olympic-sized swimming pool has a volume of between 2,500 m^{3} and 3,750 m^{3} depending on its depth, i.e. between 2.5 and 3.75 million litres. To facilitate the calculations, we will take an average volume of 3,125 m^{3}. One billion litres of water represents 320 Olympic swimming pools!

## One billion dollars

If you saved 274 dollars a day, every day, it would take you 10 years to put aside 1 million dollars. That sounds almost feasible. After all, it’s “only” $1,666 a month. In any case, the order of magnitude of this sum remains understandable.

Now, if you were given $10,000 per day, every day, for 50 years, you would have received only $182.6 million at the end of that period. In order to reach one billion dollars, you would have to earn 5.4 times as much, or $54,700 per day for 50 years, or $1.66 million per month.

## One billion people

The number of inhabitants by square mile in New York City is 27,751. If we would make one billion people live in New York City with the same density, the city would need to occupy a surface equivalent to the state of Indiana.

## One billion grains of sand

Counting the grains of sand on a beach or extrapolating the number of grains of sand on the planet is based on too many assumptions. However, we can start from the size of a fairly fine grain of sand (1 mm^{3}) and calculate how many fit into 1 m^{3} of sand.

Since one cubic metre equals exactly one billion cubic millimetres, there are already a billion grains of sand in one cubic metre of sandy beach.

## One billion stars

When the night sky is clear and free of light pollution, we can see with the naked eye about 3,000 stars of magnitude 6 (6,000 if we add the two hemispheres).

It can feels a lot, and yet it’s very little, since our galaxy, the Milky Way, counts about 200 billion stars.