How many bits are in a terabyte?

One SI terabyte (TB) equals 8,000,000,000,000 bits (8 × 10^12). One IEC tebibyte (TiB) equals 8,796,093,022,208 bits (8 × 2^40). The ~9.95% gap exists because drive makers use SI (powers of 1000) while operating systems count in binary (powers of 1024).

What is the difference between TB and TiB?

TB (terabyte) is the SI decimal unit: 1 TB = 1,000,000,000,000 bytes. TiB (tebibyte) is the IEC binary unit: 1 TiB = 1,099,511,627,776 bytes. Hard drive makers label in TB; Linux, Windows, and macOS report sizes in TiB but often display the label "TB."

How do I convert terabytes per second to terabits per second?

Multiply by 8: 1 TB/s = 8 Tbps. So a 2 TB/s link runs at 16 Tbps. This tool converts terabytes to bits, giving you the raw bit count; for per-second throughput just divide or multiply by your time window.

Why does my 1 TB drive show fewer bits than expected?

If your OS reports the drive in TiB (binary) but labels it "TB," 1 TB of OS-reported capacity is actually 1 TiB = 8,796,093,022,208 bits, not 8,000,000,000,000. Use the TiB option in this converter to match the OS figure.

Can I enter fractional terabytes?

Yes. The input accepts any positive decimal number, including values like 0.5 TB or 2.75 TiB. JavaScript floating-point arithmetic handles the full range of practical storage sizes accurately.

Terabytes to Bits Converter

Enter a terabyte value and instantly see the equivalent in bits — both SI decimal (1 TB = 8,000,000,000,000 bits) and binary IEC (1 TiB = 8,796,093,022,208 bits).

Input Value

Amount

Convert from

Quick Reference

1 TB (SI) = 8,000,000,000,000 bits
1 TiB (Binary) = 8,796,093,022,208 bits
1 TB/s = 8 Tbps

Results

Enter a value and click Convert to see results.

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Summary

This converter takes a terabyte (or tebibyte) value and outputs the exact bit count under both common standards. The SI decimal terabyte (TB) equals 1,000,000,000,000 bytes, so 1 TB = 8,000,000,000,000 bits — the figure used on drive packaging and in network-speed specs. The IEC binary tebibyte (TiB) equals 1,099,511,627,776 bytes, so 1 TiB = 8,796,093,022,208 bits — the value operating systems use internally. The gap between the two definitions is about 9.95%, which explains why a "1 TB" drive shows as roughly 0.909 TiB in Windows or macOS.

How it works

Enter the number of terabytes (or select tebibytes) in the input field.
Choose the input unit from the dropdown: TB (SI decimal) or TiB (binary IEC).
Click Convert (or press Enter) to compute.
The converter multiplies bytes by 8 to get bits: for SI, bytes = TB × 10^12; for binary, bytes = TiB × 2^40.
Copy any result with the copy icon next to it.

Use cases

Convert storage capacity from terabytes to bits for network throughput calculations.
Translate a "1 TB" drive spec into its exact bit count for technical documentation.
Compute how many bits a 4 TiB NAS volume represents for capacity planning.
Understand why OS-reported binary sizes differ from marketing decimal sizes.
Convert data-center or backbone bandwidth from terabytes per second to bits per second (Tbps).
Check raw bit counts when working with low-level storage or memory specifications.

Frequently Asked Questions

Last updated: 2026-06-19 · Reviewed by Nham Vu