➕ 8-Bit Ripple-Carry Adder

Click bits to toggle 0/1 · Watch carry propagate · See binary, hex, decimal results

Input A

Bit 7 → Bit 0
decimal: 0

Input B

Bit 7 → Bit 0
decimal: 0

Sum A + B

Binary (9-bit) 000000000
Decimal 0
Hex 0x000
Overflow (C₈) No

How it works

Each full adder cell computes:
S = A ⊕ B ⊕ Cᵢₙ
Cₒᵤₜ = (A·B) + (B·Cᵢₙ) + (A·Cᵢₙ)

Carry ripples from bit 0 → bit 7. Max value per number: 255. Max sum: 510 (9 bits).

🔢 8-Bit Ripple-Carry Adder

An interactive visualisation of an 8-bit ripple-carry adder — the fundamental building block of every CPU's arithmetic logic unit. Toggle bits, watch carries propagate, and see binary, hexadecimal and decimal results update live.

🔬 What It Demonstrates

How a full adder computes sum and carry-out from two input bits and a carry-in, then chains eight stages together so each carry ripples to the next. The critical path through the carry chain determines the adder's maximum clock speed.

🎮 How to Use

Click individual bits of A and B to toggle them on or off. Watch the carry chain flash through all 8 stages. Read the final result in binary, hex and decimal below the circuit.

💡 Did You Know?

The ripple-carry adder is the simplest binary adder design, but its O(n) carry propagation limits speed. Modern CPUs use carry-lookahead or Kogge–Stone adders that compute all carries in O(log n) time.