File Size Converter — Bytes ↔ KB ↔ MB ↔ GB ↔ TB
Convert between bits, bytes, KB, MB, GB, TB, and PB. Choose binary (1024) or decimal (1000) base — the difference that explains "why my 1 TB drive shows 931 GiB".
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| Unit | Value |
|---|---|
| bits | 8,589,934,592 |
| bytes | 1,073,741,824 |
| KB / KiB | 1,048,576 |
| MB / MiB | 1,024 |
| GB / GiB | 1 |
| TB / TiB | 9.7656e-4 |
| PB / PiB | 9.5367e-7 |
Binary vs decimal: RAM and OS-reported sizes use base-2 (1 KiB = 1024 B). Disk manufacturers and network speeds use base-10 (1 KB = 1000 B). A "1 TB" drive shows as ~931 GiB in your file manager — that\'s the reason.
Frequently asked
They give different answers. 1 GB decimal is 1,000,000,000 bytes. 1 GiB binary is 1,073,741,824 bytes — about 7.4% larger. Hardware makers use decimal (bigger number, same product). Operating systems and RAM use binary. Both are correct within their conventions.
Binary for RAM, virtual machine allocations, and file sizes reported by macOS/Linux. Decimal for disk marketing sizes, network transfer rates (Mbps = megabits/sec = decimal), and cloud storage billing.
1 byte = 8 bits. Storage and file sizes use bytes (B, KB, MB…). Network speeds use bits (b, Kb, Mb…) — that's why "100 Mbps" internet downloads a 100 MB file in about 8 seconds, not 1.