More on aligning and formatting numbers


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.


  1. Richard

    Or a thousands separator period, etc., for languages that don’t use commas!

    And on that topic – I’ve seen spaces used on occasion for thousands separators (1 000 000). Does anyone have a preference for commas over spaces, or vice versa?

  2. Anders Henricsson

    Great post Andrew! One thing I would like to know more of is how to format tables when you have really large units with large numbers, and later use the same table for showing units with really small numbers? That would be really helpful.


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