VPN Overhead & Effective Throughput
Estimate the packet overhead and expected throughput of WireGuard, OpenVPN or IPsec on top of your line speed, free online.
About this calculator
A VPN wraps each packet in extra headers, which lowers the usable MTU and payload efficiency: WireGuard adds about 60 bytes (IPv4) / 80 (IPv6), IPsec ESP about 73, OpenVPN-UDP about 100 and OpenVPN-TCP about 120. Effective throughput ≈ line speed × (MTU − overhead) ÷ MTU. CPU limits can lower it further.