WireGuard Throughput Calculator
Estimate WireGuard tunnel throughput from link rate, packet size and per-core crypto performance.
Inputs
Expected Throughput
959.5Mbps
Link-limited Goodput
959.5Mbps
Crypto Ceiling
6,000.0Mbps
Protocol Overhead
4.05%
Packet Rate
81.0kpps
Limiting Factor
Link rate bound
Step by step
Values used
Link rate = 1,000 Mbps; Inner packet size = 1,420 bytes; CPU cores handling crypto = 4 cores; Crypto throughput per core = 1.50 Gbps; Outer IP version = IPv4 outer (60 B total)
WireGuard Throughput
throughput = min(link rate × payload ÷ (payload + 60), cores × per-core crypto rate).
Expected Throughput
= 959.5 Mbps
Link-limited Goodput
= 959.5 Mbps
Crypto Ceiling
= 6,000.0 Mbps
Protocol Overhead
= 4.05
Packet Rate
= 81.0 kpps
Limiting Factor
= Link rate bound
How it works
WireGuard adds a fixed 60 bytes over IPv4 (80 over IPv6), so goodput is the payload fraction of the frame. Because ChaCha20-Poly1305 runs per packet on a single core per peer flow, the CPU ceiling — cores multiplied by per-core rate — often binds before the link does. Knowing which ceiling binds tells you whether to buy more bandwidth or more cores; on a 10G link a 4-core box will usually cap around 6 Gbps regardless of circuit size.
Formula
WireGuard Throughput
throughput = min(link rate × payload ÷ (payload + 60), cores × per-core crypto rate).
- 60
- WireGuard overhead: outer IPv4 20 + UDP 8 + WireGuard header 16 + Poly1305 tag 16
- efficiency
- Payload bytes divided by total wire bytes
Frequently Asked Questions
How is WireGuard Throughput calculated?
throughput = min(link rate × payload ÷ (payload + 60), cores × per-core crypto rate). WireGuard adds a fixed 60 bytes over IPv4 (80 over IPv6), so goodput is the payload fraction of the frame. Because ChaCha20-Poly1305 runs per packet on a single core per peer flow, the CPU ceiling — cores multiplied by per-core rate — often binds before the link does.
Why does WireGuard Throughput matter?
Knowing which ceiling binds tells you whether to buy more bandwidth or more cores; on a 10G link a 4-core box will usually cap around 6 Gbps regardless of circuit size.
What values do I need to enter?
This calculator takes 5 inputs: Link rate, Inner packet size, CPU cores handling crypto, Crypto throughput per core, Outer IP version. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.