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VPN Throughput Calculator

Calculate VPN tunnel throughput and encryption overhead

Raw bandwidth of the network link before VPN overhead.
Mbps
Encryption adds per-packet overhead bytes and CPU processing cost.
Hash used for integrity check (HMAC). Larger hashes add more bytes per packet.
IPsec tunnel mode adds new IP header (20 bytes). Transport mode only adds ESP. SSL/TLS adds TCP+TLS overhead.
tunnels

Results

Encryption Overhead per Packetbytes
Throughput Reduction%
Effective ThroughputMbps
Per-Tunnel BandwidthMbps
Overhead Bandwidth LostMbps
Effective MTU (from 1500)bytes
How it works: VPN overhead includes ESP header (8 bytes), IV (varies by cipher), padding (avg half block), HMAC (12 bytes truncated), plus encapsulation headers. IPsec tunnel mode adds 20-byte outer IP header. CPU overhead factor accounts for encryption processing cost.