🔍 Minterms and Truth Table Rows

Written and maintained by the PhDino author · Last reviewed 21 September 2026 · Checked against 2 independent reference calculations · how PhDino checks its numbers

How a single number (a minterm) encodes one specific row of a truth table.

A minterm is simply a numbered row of a truth table, encoded as a single integer for convenience. For a function of 4 variables (conventionally A, B, C, D), minterm number 6 written in binary is 0110 — meaning A=0, B=1, C=1, D=0 for that specific row. This numbering is exactly how textbooks and tools compactly describe "the function is 1 for minterms 2, 6, 7, and 13" instead of writing out a full four-column truth table every time.

Reading a minterm back into its variable assignments is just binary decoding: the minterm's binary representation, padded to the number of variables, gives each variable's value directly, most-significant bit first.

Key formula

Minterm (binary, MSB first) = A B C D
e.g. minterm 6 = 0110₂ → A=0, B=1, C=1, D=0

Notes & limitations

• This fixes the scope at exactly 4 variables (A–D), the most common textbook and K-map convention — the same binary-decoding idea extends to any number of variables, just with more (or fewer) bits to read off.
• Minterm numbering and Karnaugh map position are two views of the same underlying truth table row — see the Karnaugh Map Position article for how a minterm number translates into a specific K-map cell.