Typography Unit Converter

[PLEASE READ FIRST]

This app does not show type at its actual size, and it holds no typefaces.

It takes a number and rewrites it in another unit. That is all it does.

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🔠 Typography Unit Converter — one size, written four ways

13 Q is 3.25 mm. 9 pt is 3.175 mm, and that is exactly 12 px.

Q and ha … Japanese typesetting, carried over from phototype

point … page layout software and Western typesetting

mm … what the printer works in, on paper

px (1/96 in) … specifications for the web

A single job can involve all four at once.

Copying one into another is where mistakes happen. That is what this app is for.

■ Eight units, any direction

Q (kyu) / Ha / pt (DTP) / pt (US) / pica / px (1/96 in) / mm / inch.

Enter one number and the other seven answer at once.

Everything runs through millimetres, and all eight are defined values,

so the numbers do not shift from one reference to the next.

■ 4 Q is exactly 1 mm

Q is 0.25 mm so that it sits on the metric system without a remainder.

1 mm is 4 Q; 3 mm is 12 Q. Moving between type size and paper size is

arithmetic you can do in your head. A point is 0.352778 mm, which never

lands on a round figure. That is why Q survived in Japanese typesetting.

■ Q and ha are both 0.25 mm

Type 13 and you get "13 Q" and "13 Ha" side by side. Nothing is broken.

Q is the size of the character itself; ha is the pitch from one line to the next.

They measure different things and happen to be the same length.

On a phototypesetting machine the dial that set the size was the kyu,

and the toothed wheel that advanced the paper was the ha.

The app tells them apart in the reading under each unit.

■ There are two things called a point

The DTP, or PostScript, point is 1/72 inch, 0.352778 mm.

The US point is 1/72.27 inch, 0.351460 mm.

The gap is 0.375 percent, which comes to 0.1318 mm over 100 points.

Both are here, so figures from old metal type references and TeX go straight in.

■ About px (1/96 in)

The CSS px is defined as one ninety-sixth of an inch.

96 to 72 is 4 to 3, so 4 px is exactly 3 pt and 16 px is exactly 12 pt.

It is an agreed length, not one of the physical dots you can see.

How fine those are differs from one device to the next, so this app leaves them alone.

■ Pica

1 pica is 12 points. An inch is 6 picas, 72 points, 25.4 mm.

Western typesetting gives the size of the type in points, and the length

of a line or the width of a column in picas.

■ A quick table and six shortcut buttons

The buttons are 4 Q, 13 Q, 9 point, 16 px, 1 pica and 1 inch.

There are seven short notes, one of which lists common sizes from 8 Q to 32 Q.

In that list Q and mm are exact, while points are rounded to four decimals.

■ Good for

▪ Finding out how many millimetres a 13 Q body size comes to

▪ Turning a manuscript marked 9 pt into the size it will print at

▪ Checking what 16 px on the web becomes in points on paper

▪ Seeing how far an old reference's point sits from today's DTP point

▪ Putting a column width given in picas back into millimetres

■ Features

▪ No account, no sign-in. The calculation is done on your device, and the numbers you type are not sent anywhere

▪ One screen only. There is no settings page

▪ Japanese and English (follows the device language)

▪ Five recent entries, tap to bring one back

▪ A quick table and seven short notes

▪ A converter only. Nothing is drawn at printed size, and no lettering is included

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NISAKE GAME