Glossary entry

Rule of Thirds

noun · / ruːl əv θɜːdz / · composition guideline

A composition guideline that divides an image into a 3×3 grid (two equally-spaced horizontal lines and two equally-spaced vertical lines), creating four intersection points. The guideline holds that placing important subjects on or near these intersections — rather than centred — produces more visually engaging compositions. First documented by John Thomas Smith in his 1797 book Remarks on Rural Scenery.

By Sarah Chen · Last updated 15 May 2026

Origin

The rule of thirds takes its written form from John Thomas Smith (1766–1833), an English landscape painter and engraver. In Remarks on Rural Scenery (1797) Smith wrote: "Two equal parts will be found nearly equal in beauty; and the same thing applies to all the divisions which the eye can readily measure. The most pleasing of these is the division in thirds." Smith credited an unnamed older painter for the principle, suggesting the rule was already in workshop circulation before he wrote about it. The book was a teaching text for landscape painters of the picturesque tradition.

Mechanics

The rule divides the frame at 33.3% and 66.6% on both axes, producing a 3×3 grid of nine equal cells. The four points where the horizontal lines cross the verticals are the intersection points — the recommended placement for the main subject of the image. For images with horizon lines (landscape, seascape, cityscape), the horizon should sit on the upper or lower third — never bisecting the centre.

Modern use

The rule of thirds was reinforced through 19th-century landscape painting (William Gilpin's picturesque tradition, the Hudson River School) and adopted by 20th-century photographers when digital cameras began including thirds grids in their viewfinders. Today every smartphone camera and most DSLRs and mirrorless cameras include the option, often enabled by default. The rule is the universal composition default in photography, illustration, film, and graphic design.

In Grid Maker Pro

The rule of thirds is implemented as the Rule of Thirds overlay — one of eight overlays in the Composition category. A dedicated Rule of Thirds tool landing page hosts the live tool with adjustable intersections, one-click switching to Golden Ratio Phi grid, and bulk overlay mode for shoot review.

Related terms

Golden ratio — the refined alternative dividing at 38.2 / 61.8.
Golden spiral — Fibonacci spiral derived from the golden ratio.
Diagonal method — Edwin Westhoff's 2007 alternative based on bisecting diagonals.
Rule of fifths — modern 5×5 alternative for portrait and product photography.

Citations

Smith, John Thomas. Remarks on Rural Scenery. London: Nathaniel Smith, 1797.
Gilpin, William. Three Essays on Picturesque Beauty. 1792.
Adobe Lightroom documentation. Crop overlay options including Rule of Thirds.

Definition

Rule of thirds — a compositional guideline dividing the frame into nine equal cells using two vertical and two horizontal lines at 1/3 and 2/3. The four interior intersections are the power points; placing a subject of interest on one produces an off-centre composition that most viewers find more dynamic than dead-centre placement.

The rule produces "consistently better than centred" — not "consistently best." It works for roughly 75% of subject types (landscape with off-axis focal point, environmental portrait, snapshot). It actively hurts compositions involving symmetric subjects, tight portraits, or strong rotational geometry.

Etymology and origin

The rule was first published by John Thomas Smith in Remarks on Rural Scenery (London, 1797), as a guideline for landscape painting. Smith presented it as a way to "give pleasing intervals" between the principal masses of a composition; he was explicit that breaking the rule was sometimes the right move.

The rule existed implicitly in Renaissance painting (Da Vinci's Last Supper roughly places Christ at the upper-thirds intersection). Modern photography re-popularised it via Canon's 1976 AE-1 viewfinder grid; every smartphone since the iPhone 4 ships a thirds toggle.

Sources

Smith, John Thomas. Remarks on Rural Scenery; with Twenty Etchings of Cottages, from Nature. Nathaniel Smith, London, 1797.

Arnheim, Rudolf. Art and Visual Perception. University of California Press, revised 1974. The perceptual case for off-axis placement.

Freeman, Michael. The Photographer's Eye. Focal Press, 2007. Modern photography-school treatment.