How many bytes are in 1 TB?

In the SI decimal standard used by storage manufacturers, 1 TB = 1,000,000,000,000 bytes (10^12). This is the number you see advertised on hard drives and SSDs.

What is the difference between TB and TiB?

TB (terabyte) uses base-10: 1 TB = 1,000,000,000,000 bytes. TiB (tebibyte) uses base-2: 1 TiB = 1,099,511,627,776 bytes. Drives are sold in TB; operating systems typically report in TiB, so a 1 TB drive shows as roughly 0.909 TiB in Windows or macOS.

How many bytes are in 1 TiB?

1 TiB = 2^40 = 1,099,511,627,776 bytes. This binary standard is defined by IEC 80000-13.

Why does my 1 TB drive show less than 1 TB in my OS?

Drive manufacturers measure in SI TB (10^12 bytes), while operating systems display in binary TiB (2^40 bytes). A 1 TB drive holds exactly 1,000,000,000,000 bytes but shows as about 0.909 TiB in Windows or macOS.

How do I convert terabytes to bytes manually?

Multiply your TB value by 1,000,000,000,000 for SI decimal bytes, or by 1,099,511,627,776 for IEC binary bytes (TiB). For example, 2 TB = 2,000,000,000,000 bytes.

Terabytes to Bytes Converter

Convert terabytes to bytes using SI decimal (1 TB = 1,000,000,000,000 B) or binary IEC (1 TiB = 1,099,511,627,776 B).

Terabytes to Bytes

Terabytes

Standard

SI decimal (TB = 10¹² B) IEC binary (TiB = 2⁴⁰ B)

Enter a value to see the byte conversion

Quick Reference

Terabytes	Bytes (SI · TB)	Bytes (IEC · TiB)

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Summary

Enter a value in terabytes and instantly see the equivalent in bytes. Supports both SI decimal (TB) and IEC binary (TiB) standards so you get the right number for hard drive capacity, data transfer, or storage planning.

How it works

Enter a terabyte value in the input field.
Select SI decimal (TB) or IEC binary (TiB) standard.
The byte result appears instantly below.
Click Copy to copy the raw byte number to your clipboard.

Use cases

Calculate exact byte count for hard drive or SSD capacity comparisons.
Determine storage requirements for large backups or database archives.
Convert cloud storage quotas from terabytes to bytes for API calls.
Verify data transfer sizes when provisioning bandwidth or network throughput.

Frequently Asked Questions

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