What it does

A spreadsheet formula can be very long, and a long equation drawn as a single line runs out across columns that have nothing to do with it. Wrap breaks it at the +, − and × that join its terms, so it occupies a block rather than a strip.

The break is placed before the operator, so a continued line opens with the sign that continues it — which is how the same equation would be broken by hand.

The widths

Each setting is a number of characters a line may reach before the next operator becomes a place to break it.

Never

One line, however long. This is the default.

Very long lines — about 80 characters

Only the longest formulas are broken at all.

Long lines — about 55 characters

Comfortable for an equation with a column or two to itself.

Medium lines — about 35 characters

A good default for an equation sitting beside a table of figures.

Short lines — about 20 characters

A narrow block, for a margin or a column of its own.

The count is of what you see, not of what is written. LaTeX markup does not push a line over: a fraction costs whatever is in its numerator and denominator, and nothing for the \frac itself. A symbol does count — \alpha is one character, because it draws one letter.

Aligning on the equals sign

With Equate switched on, a wrapped equation is set out so its name and its lines sit in separate columns:

x =   a + b + c + d + e
        + f + g + h + i
        + j + k + l

Without a name in front of it there is nothing to align to, so the lines are simply broken.

Where it will not break

A break is only taken where it can be read as one. Nothing is broken inside a fraction, inside brackets, or inside a matrix: those are single objects, and a line ending halfway through one would be wrong rather than merely long. A matrix that sits inside a longer formula is wrapped around, never within.

Wrapping changes the equation itself rather than how it is drawn, so changing this setting redraws the equations on the sheet.