'measure of righteousness'; Russian: Мерило Праведное, Church Slavonic: мѣрило праведноѥ) is a Russian collection of writings from the late 13th or early 14th century, preserved in the copies of the 14th to the 16th centuries.

The name was given in modern literature, taken from the first words of this text: "this books is just measure, true weighing..." ("siya knigi merilo pravednoye, izves istin`nyi..." or "сиѩ книги мѣрило праведноѥ.

Just Measure was written in Church Slavonic and Old Russian.

Materials from the old legal collection from the early 12th century may have been used during the compilation of Merílo Právednoye.

The text consists of two parts: the first contains the words and the lessons (poucheniya) both translated and original, on the just and the unjust courts; the second part (the so-called collection of 30 chapters) consists of translations of Byzantine church and secular laws, borrowed from the Kormchaia Book, and the oldest Slavic and Russian legal texts, the Zakon Sudnyi Liudem, Vladimir's Church Statute, Russkaya Pravda, and "Legal rule on the church people" – Pravilo zakonno o tserkovnykh liudiakh.