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ELECTRICALResources / Electrical symbolsUpdated 29 Oct 2026

Logic gate symbols: AND, OR, NOT, NAND, NOR, XOR

Logic gates combine binary signals: AND, OR and NOT, and the inverted and exclusive forms built from them. They appear in digital electronics, PLC function block diagrams and interlock logic.

SymbolANSI / IEEEIEC 60617What it is
AND gateThe output is 1 only when all inputs are 1.
OR gateThe output is 1 when at least one input is 1.
NOT gateThe output is the opposite of the input.
Buffer gateThe output equals the input, with more drive.
NAND gateThe output is 0 only when all inputs are 1: an AND gate followed by NOT.
NOR gateThe output is 1 only when all inputs are 0: an OR gate followed by NOT.
XOR gateThe output is 1 when the inputs differ.
XNOR gateThe output is 1 when the inputs are the same.

Logic gates: ANSI and IEC

This is where the two standards look most different. ANSI / IEEE 91 uses distinctive shapes: a D for AND, a shield for OR, a triangle for NOT. IEC 60617 draws every gate as the same rectangle and tells them apart by the qualifying symbol inside: & for AND, ≥1 for OR, 1 for a buffer or NOT, =1 for XOR.

A small circle at an output means it is inverted: NAND is AND with a circle, NOR is OR with a circle.

Frequently asked questions

Which logic gates appear on a electrical schematic?

This legend covers AND gate, OR gate, NOT gate, buffer gate, NAND gate, NOR gate, XOR gate, XNOR gate. Project legends may add more.

Are these symbols different in IEC and ANSI?

8 of the 8 are drawn differently. Each symbol page shows both forms side by side.

Can I download these symbols?

Yes. Each symbol page has free SVG files, and the hub has printable PDF charts.

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