In this post, I stated the rule that numbers within tables should always be right aligned. There are a few extensions to this rule that are worthy of mention.
- Align numbers containing decimal points so that the decimal points are all aligned. This means that all numbers in a column must be displayed to the same number of decimal places.
- When brackets are used to identify negative book-keeping numbers, the numbers should still be right aligned to the decimal point or to the right-most digit when there is no decimal point. In Excel, you can achieve this by using this custom format or similar: _(* #,##0.00_);_(* (#,##0.00);_(* “-“??_);_(@_)
- When displaying percentages, always include the percentage sign (%) after the number and ensure these are aligned.
- Do not exceed the required level of precision. Numbers stated to an overly high degree of precision are more difficult to assimilate and create a busy table that can look like a wall of numbers.
- Scale numbers in thousands, millions, billions etc when this does not compromise the required level of precision, but do so consistently within a given table.
- Always use a thousands separator comma for larger numbers.