CRC Calculator - CRC8/16/32 Online | EasyFPGA CRC RTL Builder

1Select a preset (e.g. CRC-32 for Ethernet) or enter custom polynomial parameters below.
2Enter input data — choose HEX, ASCII, or Binary tab.
HEX example: 31 32 33 | ASCII example: 123456789
3Click Calculate to get the CRC result in HEX / Decimal / Binary / Verilog literal.
4Scroll to RTL Generator → set Data Width → click ⚡ Generate RTL + Testbench.
5Click 📋 Copy or ⬇ Download to save the .sv files for Vivado / Icarus simulation.

💡 The Self-Test section at the bottom verifies both the calculator and RTL generator against known CRC vectors (e.g. CRC-32 of "123456789" = 0xCBF43926).
For a deeper explanation of CRC theory and RTL implementation, see the full guide on EasyFPGA.blog →

⚙️ Calculate

Input Data

HEX input: separate with spaces or commas (e.g. 31 32 33 or 0x31,0x32)

Width (bits)

Polynomial (HEX)

Init Value (HEX)

XOR Out (HEX)

Reflect Input

Reflect Output

CRC Result

0x00000000

HEX

Decimal

Binary

Verilog

Click any value to copy

💻 RTL Generator (SystemVerilog)

Generates a synthesizable SystemVerilog module based on the CRC parameters configured above.

Data Width (bits/clock)

Module Name

📚 Common CRC Standards

CRC-32

Poly: 0x04C11DB7

Most widely used CRC. Excellent error detection.

✅ Ethernet, ZIP, PNG, MPEG

CRC-32C

Poly: 0x1EDC6F41

Hardware-optimized variant of CRC-32.

✅ iSCSI, SCTP, SSD, NVMe

CRC-16/CCITT

Poly: 0x1021

Widely used in communication protocols.

✅ X.25, HDLC, Bluetooth

CRC-16/MODBUS

Poly: 0x8005

Industrial communication standard.

✅ MODBUS, industrial equipment

CRC-16/IBM

Poly: 0x8005

General-purpose 16-bit CRC (USB, etc.).

✅ USB, ARC

CRC-8

Poly: 0x07

Simple CRC for small packets.

✅ I2C, SMBus, sensors

🧪 Self-Test

Verifies the Calculator and RTL evaluator agree on all standard presets using the IEEE test vector "123456789". Runs automatically on page load.

🔢 CRC Calculator

⚙️ Calculate

💻 RTL Generator (SystemVerilog)

📚 Common CRC Standards

🧪 Self-Test

🚀 Implement it on FPGA!