Representing large numbers

I'm developing a charting application. There could be a situation where I would have to display large numbers on the chart. The problem is that they number labels have to fit inside the chart columns, which are limited in space and I have only 4 characters to display the numbers.

I am currently using multipliers, so that e.g. 1234567 is displayed as 1.2M. I like this solution, but while K is an acceptable suffix for thousands, there's no such suffix for billions.

What can I do to remedy this? Any good ways of displaying the data?

Some ideas :

• Are you sure you only have 4 characters to display the numbers? You should think pixels instead of characters. Maybe you can use a 8 pixels police that would make you gain a character.
• Can't you use a magnifier, a tooltip or something else of that kind?
• If it is a charter application, I guess numbers are important: if you have only 4 characters to display it the chances are great the interface is not ready.
• You are probably not going to compare millions with billions or thousands: why don't you name the numbers column adequattly ? For instance: `Turn-over in billions`

There is a standard prefix for billions, and that is a `G`. Anything using a computer user uses the SI metric prifixes, and most people are used to talking about GB (and even TB) already. So I would recommend sticking to the SI metric prefixes.

The problem with using `B` or `Billion` is that the word 'billion' has two meanings depending on the country that you are referring to. These are referred to as long and short scales. In some it is 10^9 while in others it is 10^12, so you are going to cause confusion with a fair amount of people by doing this.

Using 'G' as a 'billion' symbol is at least not ambiguous and people that commonly deal with file sizes or space on a computer are likely to know what it means.

The alternate method which is used in many engineering applications is to either write it as `5.4 x 10^9` or as `5.4E9`. This is not something that I would recommend to any non-technical users though.

• 'G' can sometimes be ambiguous: it is sometimes used when 'Gi'(2^30) is meant. (Bandwidths are usually Gb/s, memory capacities use GiB but often written as GB, disk capacity seems to use GB.)
– user43012
Commented Feb 14, 2014 at 0:46

I'd say you have 2 possible solutions.

1. When in the billions, only use 1 digit, followed by Bn
2. Use B

I think in the context of money, people will understand what B means, especially if they know they're dealing with large quantities of money.