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Trim Marks

Copyfitting Calculator

How deep your copy runs, and whether the measure works.

The copy

The setting

How much space it takes

Characters per line
36
Lines
84
Depth
98.0 picas
Depth
16.33 in

A measure of 36 characters is narrow. Below about 45 the eye returns too often and the rag gets ugly.

Type scale from this size

  • Trim Marks24.41pt
  • Trim Marks19.53pt
  • Trim Marks15.63pt
  • Trim Marks12.50pt
  • Trim Marks10.00pt · base
  • Trim Marks8.00pt
  • Trim Marks6.40pt

Depth is an estimate, as every copyfitting method has been. Real depth depends on the font’s own metrics, your tracking, hyphenation settings and where the lines happen to break. This gives you the number to plan a layout around — which is exactly what the printed copyfitting wheels did.

Enter a character count — or paste the text and let it count — plus your point size, leading and column width, and get the depth in picas and inches. It also tells you the measure in characters per line and whether that falls in the comfortable range, which is the number typographers actually judge a column by.

01

Why use this tool?

Depth in picas and inches

The number you need to plan a layout, in the units the job is specified in.

Judges the measure

Warns when a column falls outside the comfortable 45–75 characters per line.

Counts your text

Paste the copy and it counts characters and words for you.

Type scale included

Generates a modular scale from your base size, in eight standard ratios.

02

How this copyfitting calculator works

Characters per line is the column width divided by the average character width, and average character width is expressed as a fraction of the point size. A serif text face runs around 0.5em, a condensed face nearer 0.42, a wide slab nearer 0.58. Choosing the right one changes the estimate materially, which is why it is a control rather than a constant.

Lines are the character count divided by characters per line, rounded up, and depth is lines multiplied by leading. That is exactly the arithmetic the printed copyfitting wheels did, and it is exactly as approximate — real depth depends on the font's own metrics, your tracking, hyphenation settings and where the breaks happen to fall.

The measure is the number worth watching. Between about 45 and 75 characters a line is the comfortable range for continuous reading: narrower and the eye returns too often, wider and it struggles to find the start of the next line. The tool flags a column that falls outside it, because a layout that fits perfectly and reads badly has not actually solved the problem.

03

How to use it

  1. Step 1: Give it a character count

    Or paste the actual copy.

  2. Step 2: Set the type

    Point size, leading and column width in picas.

  3. Step 3: Check the measure

    Below 45 or above 75 characters a line and the column will be uncomfortable to read.

04

Example usage

Fitting an article
A word count from an editor turned into a depth, to see whether it fits the space before anyone starts cutting.
Planning a brochure
Working backwards from available depth to find how much copy each panel can carry.
Checking a column
An existing layout tested for measure, to explain why a page feels harder to read than it should.
05

Why estimating still matters when text is dynamic

Copyfitting looks like a survival from hot metal, when a page had to be planned before it could be set and getting it wrong meant resetting. Digital layout removed that penalty: text reflows, and you can see the real answer immediately. The estimating step became optional, and mostly disappeared.

It came back through the front door. Content managed in a CMS, syndicated across templates, or fed by an API is not a known quantity when the layout is designed — the designer is specifying a container for text that does not exist yet. Knowing that a card breaks above roughly 90 characters is the same calculation as fitting a column, applied to a range rather than a fixed piece of copy.

Localisation makes it sharper still. Translating English into German commonly adds 20 to 35 per cent to the character count, and short interface strings can expand far more than that in proportional terms — a one-word button label is the worst case, because there is no long text for the average to hide in. Designing to the English string and hoping is how a translated interface arrives full of truncation. Estimate the expanded length and design the container for that.

06

Frequently asked questions

How accurate is a copyfitting estimate?

It is an estimate, as every method has been. Real depth depends on the font's metrics, tracking, hyphenation and where lines break. It gives you a number to plan around, which is what the printed copyfitting wheels did.

What is a good measure?

Between about 45 and 75 characters a line for continuous text. Narrower and the eye returns too often; wider and it loses its place finding the next line.

What does average character width mean?

How wide the average character is as a fraction of the point size. A condensed face runs around 0.42em, a serif text face around 0.5em, a wide slab nearer 0.58em. Picking the right one materially changes the estimate.

How much does text expand when translated?

German, Finnish and Russian commonly run 20 to 35 per cent longer than English in running text, and short interface strings can expand far more in proportional terms. Asian languages are usually shorter in character count but often need more vertical space. Design containers for the longest expected language, not for the English.

Does copyfitting still matter on the web?

More than it looks. Any layout fed by a CMS or an API is a container designed for text that does not exist yet, so knowing where a card or a heading breaks is exactly the old calculation applied to a range instead of a fixed piece of copy. It is the difference between a template that degrades gracefully and one that only works with the sample content.

How do I get an accurate character count?

Word processors report it directly, usually with and without spaces — use the figure including spaces, since a space occupies a character position on the line. If you are pasting into this tool it counts for you. For a rough conversion, English averages a little under six characters per word once spaces are included.

07

Related tools

Browse every tool in Layout & Measurement Tools.