Baseline Grid Calculator
Snap a desired line height to the nearest multiple of a baseline unit, and work out how many lines fit on a page for consistent vertical rhythm.
Snapped to the grid
Keeping a layout in rhythm
Baseline grids matter most where several text elements share a page: a poster with a headline, a subhead, and a caption; a book page with a running head, body copy, and a footnote; a multi-column layout where text needs to line up across the gutter. Without a shared grid, each element's own natural line height pulls it slightly out of step with its neighbours, and the misalignment becomes visible the moment two columns sit side by side.
The fix is to decide on one baseline unit for the whole document and round every other line height up or down to a whole multiple of it, exactly what this calculator automates. It's a habit borrowed from print typography that still holds for on-screen layout and lettering compositions alike.
Frequently Asked Questions
What is a baseline grid, and why bother with one?
A baseline grid is a repeating vertical measurement — usually your body-text line height — that every text block on a page is aligned to. When headings, captions, pull quotes, and columns of body text all snap to the same underlying rhythm, their baselines line up across a spread even though the type sizes differ, which is what gives a printed page or poster its sense of order.
How does snapping actually work?
Given a baseline unit (say 24px) and a line height you'd like for a heading (say 34px), the calculator finds the nearest whole multiple of the baseline unit — in this case 24px (1×) or 48px (2×) — and picks whichever is closer. A heading set at 48px instead of 34px will occupy exactly two baseline units, keeping every line after it back on the shared grid.
Why does it never snap to less than one baseline unit?
A line height shorter than a single baseline unit would break the grid outright — the next line of text would land partway through a baseline instead of on one. Rounding up to at least 1× keeps every text block's height a whole multiple of the shared unit, which is the entire point of a baseline grid.
What's the "lines per page" figure useful for?
Dividing a page or column height by the baseline unit tells you how many full lines of body text will fit — useful for planning how much copy a layout can hold before you start setting it, or for checking that a design's margins leave a whole number of baselines rather than a partial line at the bottom.
Educational tool only. Snapping is exact arithmetic based on the baseline unit you supply — the right unit for your project depends on your body-text size and design system.