Consistently use the same formats and units throughout
It is great to be able to make Excel convert numbers from whole numbers to thousands to millions and back again.
But this continuous manipulation of the format of the numbers introduces risk especially if it is in the inputs and calculations sections.
Same with units. Going from miles to kilometers is nice but will you always remember what metric you are working in and more importantly will the users remember to enter the numbers in the correct format?
Use the same formats and units throughout
Decide upfront and be consistent on the format of the data you need as an input and throughout your calculations.
Are amounts going to be shown as whole numbers, in thousands or millions? What units are you using, kilograms or pounds, kilometers or miles, hours or days?
By being consistent in this aspect, you avoid having to worry about whether the numbers have been correctly converted and treated like for like.
In the video clip below we show how this can be confusing and in all cases, confusion in a spreadsheet increases the likelihood of errors.
To follow along go to 1.9 and 1.10
If YouTube doesn't work, click here