Mechanical Calculators is one of the Technologies in Frostpunk. It is necessary to unlock the third tier of technologies.
The Mechanical Calculators technology is the third of 5 special technologies which do not unlock anything directly related to the game world, but instead allow the researching of other technologies by expanding the Workshops' capacity to research. The technology following Mechanical Calculators is Difference Engine. The prerequisite to researching Mechanical Calculators is Drafting Machines, having any workshops with working engineers, and 100 Wood and 50 Steel.
The regular technologies unlocked by Mechanical Calculators are, by technology tab:
: exclusive to The Arks
: exclusive to The Last Autumn
: exclusive to The Fall of Winterhome
: not available in Endless mode
: not available in The Arks