# Compare equations

Equations for the same trees often disagree by 30% or more. The page plots several equations on one chart across diameters. It runs in the browser.

- Only equations that take DBH can be plotted; ids of other equations are ignored. Height, wood density and E are set once for all curves, so an equation that needs another input (such as palm stem height) plots nothing.
- Open a comparison directly: https://treeallometry.org/compare/?ids={id},{id},… (ids from https://treeallometry.org/llms.txt or https://treeallometry.org/data/equations.json)
- To compute values yourself, use each equation's canonical form ("expression" in the data) with DBH in cm, height in m and wood density in g/cm³.