Encapsulation Overhead Calculator
Stack VLAN tags, GRE, VXLAN and IPsec to see total per-packet overhead, goodput and remaining MTU.
About Encapsulation Overhead Calculator
Overheads stack additively because each layer wraps the one below, so a VXLAN frame inside an IPsec tunnel with a service tag pays for all three headers. Goodput is the payload's share of the resulting frame at line rate. Stacked encapsulation is how a 10G link quietly delivers 8.9G of useful data, and it is what determines whether jumbo frames are mandatory in the underlay.
Formula
Encapsulation Overhead
total overhead = 4 × VLAN tags + 24 (GRE) + 50 (VXLAN) + IPsec ESP bytes; goodput = link rate × payload ÷ (payload + overhead).
- VLAN tag
- 4 bytes each — two for QinQ service provider tagging
- ESP bytes
- 56 for AES-GCM, up to 73 with AES-CBC and a SHA integrity check
Worked example
With the default values below, Encapsulation Overhead Calculator returns Total Overhead per Packet of 54. Change any input above and every figure here is recalculated in your browser.
Inputs used
- Inner packet sizeaccepts 64–9,000 bytes
- 1,000 bytes
- 802.1Q tags (QinQ = 2)accepts 0–3 tags
- 1 tags
- Add GRE (24 B)
- No
- Add VXLAN (50 B)
- Yes
- IPsec protectionone of None, ESP tunnel, AES-GCM (56 B), ESP tunnel, AES-CBC + SHA (73 B), ESP + NAT-T UDP (64 B)
- None
- Link rateaccepts 1–400,000 Mbps
- 10,000 Mbps
Results
- Total Overhead per Packet
- 54 bytes
- Share of the Frame
- 5.12%
- Payload Goodput
- 9,487.67 Mbps
- MTU Left from 1500 B
- 1,446 bytes
- Encapsulation Stack
- 802.1Q x1 + VXLAN 50 bytes
Step by step
- 1Values used
- 2Encapsulation Overhead
- 3Total Overhead per Packet= 54 bytes
- 4Share of the Frame= 5.12
- 5Payload Goodput= 9,487.67 Mbps
- 6MTU Left from 1500 B= 1,446 bytes
- 7Encapsulation Stack= 802.1Q x1 + VXLAN 50 bytes
Assumptions and limits
- The result is derived only from the 6 inputs listed above. Anything not among them is not part of the calculation.
- In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
- Figures are rounded for display to 2 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.
Frequently Asked Questions
How is Encapsulation Overhead calculated?
total overhead = 4 × VLAN tags + 24 (GRE) + 50 (VXLAN) + IPsec ESP bytes; goodput = link rate × payload ÷ (payload + overhead). Overheads stack additively because each layer wraps the one below, so a VXLAN frame inside an IPsec tunnel with a service tag pays for all three headers. Goodput is the payload's share of the resulting frame at line rate.
Why does Encapsulation Overhead matter?
Stacked encapsulation is how a 10G link quietly delivers 8.9G of useful data, and it is what determines whether jumbo frames are mandatory in the underlay.
What values do I need to enter?
This calculator takes 6 inputs: Inner packet size, 802.1Q tags (QinQ = 2), Add GRE (24 B), Add VXLAN (50 B), IPsec protection, Link rate. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.