I want to set up Excel so that the units throughout are millimetres.
How can i do this/
Not sure about "throughout" but:
Office icon (pretty circle top left); Excel Options (at bottom);
Advance (midway down left)
Look for Ruler and set to millimetres
Click OK at bottom
Now the ruler (when used) and Margins in Page Setup show metric units
Column width and row height are always in their own units.
best wishes

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Bernard V Liengme
Microsoft Excel MVP
http://people.stfx.ca/bliengme
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>I want to set up Excel so that the units throughout are millimetres.
> How can i do this/