Layout & Measurement Tools
The calculations that used to live on a wheel in a desk drawer, or on a laminated card pinned above the desk. Proportional scaling, picas to millimetres, how much space a given amount of copy will take, and where the columns fall on the page. None of them are difficult; all of them are tedious, and all of them are easy to get subtly wrong at eleven at night.
5 tools in this category
Fraction and Unit Converter
Decimals to fractions, and every typographic unit.
OpenProportional Scale Calculator
The percentage, the new size, and whether it crops.
OpenPage Grid Calculator
Columns, margins and baselines, drawn to scale.
OpenCopyfitting Calculator
How deep your copy runs, and whether the measure works.
OpenSpecial Character Reference
Seventy characters, and when to use each.
Open
Which point are we talking about?
There are three points in circulation and they are not the same. The PostScript point is exactly 1/72 inch and is what every design application has meant since the 1980s. The traditional American point is 1/72.27 inch. The Didot point, used across continental Europe, is different again.
The gap is about 0.4%, which is invisible on a caption and adds up to nearly a millimetre over a page depth. Everything here uses PostScript points, and says so, because a converter that does not tell you which point it means is not much of a converter.
Why picas survive
Picas look like an anachronism until you set a page in them. Twelve points to a pica and six picas to an inch means column widths, gutters and margins land on whole numbers where millimetres give you decimals with a rounding error attached.
That is the entire reason the unit persists in a trade that has otherwise gone metric. It is not nostalgia — it is that the arithmetic comes out clean.
What a grid is actually for
A grid is not a decoration and it is not a constraint on invention. It is a set of decisions taken once so they do not have to be retaken on every page — where a column starts, how wide an image can be, what the space between things is. That is what makes a fifty-page document look like one document rather than fifty.
The number of columns matters less than people think. What matters is that the number divides usefully: a twelve-column grid gives you halves, thirds, quarters and sixths, which is why it became the web default. A five-column grid gives you fifths and nothing else, which is why nobody uses one.
The part most often skipped is the vertical. A baseline grid does for horizontal alignment what columns do for vertical, and it is the difference between text that aligns across a spread and text that nearly does. It only works if the text height divides exactly by the leading, which is a single arithmetic check that saves an afternoon of nudging.
Frequently asked questions
How many points are in a pica?
Twelve, and six picas to the inch. So a pica is 1/6 inch and a point is 1/72 inch, using the PostScript definitions your software uses.
Is the copyfitting estimate accurate?
It is an estimate, as every copyfitting method has been. Real depth depends on the font's own metrics, your tracking, hyphenation settings and where lines happen to break. What it gives you is the number to plan a layout around, which is what the printed wheels did.
Why are margins called inside and outside?
Because on a spread they swap sides. What is the left margin on a right-hand page is the right margin on the next one. Naming them inside and outside is the only way to describe a facing-pages grid without ambiguity.
How wide should a column be?
Wide enough for 45 to 75 characters a line, which for most text faces at 10pt lands somewhere between 14 and 22 picas. Below 45 the eye returns too often and the rag turns ugly; above 75 it struggles to find the start of the next line. Set the measure first and let the column width follow from it.
Should I add extra margin for the binding?
For anything thick, yes. A perfect-bound book loses visible page toward the spine as the signature curves, and the allowance grows with the page count — a few millimetres for a slim book, considerably more for a thick one. Ask the binder rather than guessing; they will have a figure for the stock and method.
Do I need a grid for a single page?
Less than for a document, but it still helps. Even on one page a grid decides where things align, and alignment is most of what separates a layout that looks considered from one that looks assembled. The Van de Graaf canon is a reasonable starting point when there is no other constraint.