Fitbaseline: better baseline grids in InDesign

When we design publications, we strive for visual harmony and order throughout our composition. A fundamental tool to achieve this is the baseline grid. But the baseline grid system we are used to today can be improved to attain a higher level of harmony by ‘fitting’ the baseline grid.


The baseline grid we are used to in Adobe InDesign consists of rows of a fixed height, starting from the top of the document. When the grid reaches the bottom of the page it often overshoots, because the document height can’t be precisely divided by the baseline unit. This overshoot creates visual imbalance.

The baseline grid overshoots because the document height can’t be precisely divided by the baseline.

A better baseline

In order to fix the overshoot, we would manually calculate a baseline grid that’s an exact divisor of the document height, and as close to the desired baseline as possible. As a result, the baseline grid is evenly distributed over the document height — from top to bottom.

The baseline grid is evenly distributed over the document height.

Lost practice

This practise isn’t anything new. Before the age of printing, scribes used to divide the page in equal measures to draw a baseline that fitted the page perfectly. It was the invention of moving type that forced typographers to start using baselines of fixed values that didn’t always correspond with the page size.

Adobe InDesign takes its cues from traditional printing, and although it liberated many elements of typography from their physical restrictions, the baseline grid isn’t one of them. As such, InDesign only allows for a fixed baseline grid that isn’t equally divided over the page.


Manually recalculating the baseline every time we changed the leading was a real pain. When discussing this over a few drinks, we figured this could be solved through scripting. A few hours into midnight, we had a functional concept which eventually became Fitbaseline. A few months later, we made Fitbaseline available as an online calculator and extension for InDesign.

Easily calculate a fitted baseline by entering your document height and desired baseline in the Fitbaseline online calculator.

Online calculator

Using the Fitbaseline online calculator is simple. All you have to do is enter your document height and desired baseline in the desired unit of measurement, et voilà, the calculator outputs the value for a fitted baseline in points, which we can then use in InDesign (or any other application).

InDesign extension

The InDesign extension both calculates and applies the fitted baseline within InDesign, and over time we added some useful related options as well.

The Fitbaseline extension for InDesign is a straightforward tool. After installing the script, you can access its functionality by selecting Fitbaseline from the Layout menu.

The appearing dialog consists of three adjustable parameters:

  1. Desired baseline: Fitbaseline will approach this value as close as possible. The default value is your current baseline.
  2. Distribute grid: The same principle for distributing the baseline can be applied to the document grid as well. Fitbaseline can optionally align the vertical document grid to the baseline, and distribute the horizontal document grid according to a chosen ratio. There are three options: an approximate square, an approximate golden ratio and the page ratio.
  3. Adjust margins: Additionally, you can let Fitbaseline snap the margins in your document to the nearest grid unit, saving you a lot of time. It recalculates each page and masterpage, so it respects local overrides you made.

After you applied the settings and hit OK, Fitbaseline works its magic and provides a tiny report with the fitted baseline value and which parameters were changed.

Look at that. A flawless fit.

Everything fits! 😍

Decimal values

When working with a distributed baseline, precision is paramount. A fitted baseline often results in a decimal number, 11.906 pt for example. But since Adobe InDesign’s interface rounds all numbers, under its hood this would actually be 11.905511811018 pt.

If we would then draw a rectangle using the rounded number InDesign provides, chances are that our rectangle doesn’t precisely fit the baseline or document grid. That’s why Fitbaseline gives us the full decimal value for further use.

A baseline related unit

Fitbaseline allows us to calculate and apply an evenly distributed baseline with ease, but it often results in a complex decimal baseline value. This increases our desire for a dynamic unit of measurement within InDesign that relates to the document’s baseline. Such a unit would make it possible to express various parameters throughout the design as a multiplication or division of the document’s baseline. We would then for example be able to express a header’s leading as twice the number of baselines, or a paragraph’s space after in any number of baselines.

The unit’s relation to the document’s defined baseline means that it’s dynamic: whenever you change the baseline, every value expressed in this unit will change accordingly. There is no more need to adjust these parameters manually.

Adding such core functionality is up to Adobe, and we sincerely hope that the concept of a distributed baseline pleads for the addition of a ‘baseline unit’ to InDesign in the future.

If you like the idea of a dynamic baseline unit, join the discussion and vote for it at the InDesign uservoice site.

In the meanwhile, you can already try out Fitbaseline.