Size the multi-user MIMO gain from AP and client spatial streams, including group size, sounding overhead and stream utilisation.
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.
MU-MIMO Capacity
group size = min(AP streams ÷ client streams, clients); MU-MIMO throughput = streams used × per-stream rate × (1 − sounding overhead).
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.
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.
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.