Calculate sequential disk throughput from IOPS and block size.
Throughput and IOPS describe the same underlying I/O stream from different angles — throughput is simply IOPS multiplied by the size of each operation. This is why storage vendors quote both figures separately: a workload with small blocks (e.g. 4KB random database I/O) can hit its IOPS ceiling long before saturating available MB/s bandwidth, while a workload with large sequential blocks (e.g. 256KB video streaming) tends to hit the bandwidth ceiling first even at modest IOPS.
Throughput
throughput_MBps = IOPS × block_size_KB / 1024
Because throughput = IOPS × block size, the same device can be IOPS-limited with small blocks (yielding low throughput despite high IOPS) or bandwidth-limited with large blocks (yielding high throughput at comparatively low IOPS) — vendors typically publish both a max-IOPS spec (small blocks) and a max-throughput spec (large blocks) for this reason.
Use whichever IOPS figure matches your actual workload pattern — random IOPS for database/VM workloads with scattered access, sequential IOPS for backup/streaming/large-file workloads — since the two can differ by an order of magnitude on the same device.
Storage capacity and I/O size are conventionally expressed in binary units (1 KB = 1024 bytes, 1 MB = 1024 KB) by operating systems and most storage tooling, so dividing by 1024 keeps the throughput figure consistent with how OS-level tools like iostat or Windows Perfmon report it.