MU-MIMO Capacity Calculator
Size the multi-user MIMO gain from AP and client spatial streams, including group size, sounding overhead and stream utilisation.
About MU-MIMO Capacity Calculator
An AP can separate as many simultaneous clients as it has spatial streams, divided by the streams each client uses. Every stream in the group carries data at the full per-stream rate, so throughput scales with the group, minus the airtime spent sounding the channel to build the beamforming matrix. MU-MIMO gain collapses when clients use more streams than you assumed or refuse to group because they are physically close together, so the theoretical 4× rarely survives contact with a real client mix.
Formula
MU-MIMO Capacity
group size = min(AP streams ÷ client streams, clients); MU-MIMO throughput = streams used × per-stream rate × (1 − sounding overhead).
- usedStreams
- AP spatial streams actually carrying user data
- overhead
- Airtime spent sounding the channel and signalling the group
Worked example
With the default values below, MU-MIMO Capacity Calculator returns MU-MIMO Cell Throughput of 1,006.7. Change any input above and every figure here is recalculated in your browser.
Inputs used
- Spatial streams on the APaccepts 1–16 streams
- 8 streams
- Spatial streams per clientaccepts 1–4 streams
- 2 streams
- Clients available to groupaccepts 1–500 clients
- 20 clients
- PHY rate per spatial streamaccepts 1–5,000 Mbps
- 143 Mbps
- Sounding and grouping overheadaccepts 0–50 %
- 12 %
Results
- MU-MIMO Cell Throughput
- 1,006.7 Mbps
- Gain vs Single-User
- 3.52 ×
- Clients per MU-MIMO Group
- 4
- Single-User Throughput
- 286.0 Mbps
- AP Stream Utilisation
- 100.0%
Step by step
- 1Values used
- 2MU-MIMO Capacity
- 3MU-MIMO Cell Throughput= 1,006.7 Mbps
- 4Gain vs Single-User= 3.52 ×
- 5Clients per MU-MIMO Group= 4
- 6Single-User Throughput= 286.0 Mbps
- 7AP Stream Utilisation= 100.0
Assumptions and limits
- The result is derived only from the 5 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 MU-MIMO Capacity calculated?
group size = min(AP streams ÷ client streams, clients); MU-MIMO throughput = streams used × per-stream rate × (1 − sounding overhead). An AP can separate as many simultaneous clients as it has spatial streams, divided by the streams each client uses. Every stream in the group carries data at the full per-stream rate, so throughput scales with the group, minus the airtime spent sounding the channel to build the beamforming matrix.
Why does MU-MIMO Capacity matter?
MU-MIMO gain collapses when clients use more streams than you assumed or refuse to group because they are physically close together, so the theoretical 4× rarely survives contact with a real client mix.
What values do I need to enter?
This calculator takes 5 inputs: Spatial streams on the AP, Spatial streams per client, Clients available to group, PHY rate per spatial stream, Sounding and grouping overhead. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.