Packet Size Calculator
Calculate MSS and packet structure from MTU and encapsulation type
Input
None (Standard Ethernet)PPPoE+8BGRE+24BIPsec (Tunnel Mode)+73BVXLAN+50BMPLS (1 Label)+4B802.1Q VLAN+4B
Results
Effective MTU
1500 bytes
TCP MSS
1460 bytes
1500 - 20 - 20 = 1460
TCP MSS (with timestamps)
1448 bytes
1500 - 20 - 32 = 1448
UDP Max Payload
1472 bytes
1500 - 20 - 8 = 1472
Ethernet Overhead
18 bytes
Header (14) + FCS (4)
Header Overhead Breakdown
| Layer | Size |
|---|---|
| Ethernet Header | 14 bytes |
| IP Header | 20 bytes |
| TCP Header (no options) | 20 bytes |
| TCP Header (with timestamps) | 32 bytes |
| UDP Header | 8 bytes |
| Ethernet FCS | 4 bytes |
Packet Structure (TCP)
Ethernet Header14B
IP Header20B
TCP Header20B
TCP Payload (MSS)1460B
Ethernet FCS4B
Total frame size: 1518 bytes (Ethernet frame)