Graduated symbology — Tool (QGIS)

In QGIS: Layer Properties › Symbology, renderer Graduated. Not a Processing tool: it changes how a layer is drawn, not its data.

Realises:

Classification — through Mode: Equal Count (Quantile), Equal Interval, Fixed Interval, Logarithmic Scale, Natural Breaks (Jenks), Pretty Breaks, Standard Deviation
Classes shared between maps — with class boundaries edited by hand and the style saved and loaded on the other layers

Settings that matter

Value: a field or an expression (e.g. "samlet_areal_mean").
Mode and Classes: the method and number of classes. Classify recomputes the boundaries from the data.
Double-click a class’s Values to type its boundaries by hand; edit Legend to give classes readable labels.
Style › Save Style… writes a .qml file; Style › Load Style… on another layer applies the same classes and colours. Right-click a layer › Styles › Copy Style and Paste Style does the same between layers in a project.

Every time you press Classify or change Mode, QGIS recomputes the boundaries from this layer’s values. Two layers classified separately get different boundaries, even with the same mode; for comparable maps, set the boundaries once and copy the style.
Features with an empty (NULL) value are not drawn at all. Show them, and areas with too few points, with a separate class: use Categorized or Rule-based on an expression, as in Comparable choropleth maps (Recipe - QGIS).

Checked in QGIS 4.2.2, October 2026. Names and options can differ in other versions.