---
title: "Data Storage Converter — Bits, Bytes, MB, GB, TB to GiB (SI vs Binary)"
description: "Convert between bits, bytes, KB, MB, GB, TB, PB (SI) and KiB, MiB, GiB, TiB (IEC binary). Explains why your 1TB drive only shows 931GB in Windows."
url: "https://worldcalculators.org/calculators/data-storage/"
canonical: "https://worldcalculators.org/calculators/data-storage/"
---

# Data Storage Converter

Convert between bits, bytes, KB, MB, GB, TB, PB (SI) and KiB, MiB, GiB, TiB (IEC binary). Explains why your 1TB drive only shows 931GB in Windows.

## Quick answer

1 GB (SI) = 1,000,000,000 bytes. 1 GiB (binary) = 1,073,741,824 bytes. A "1 TB" hard drive = 931 GiB. This is why your drive shows less space than advertised — the units differ.

## Frequently Asked Questions

macOS switched to SI (decimal) units in OS X 10.6 (Snow Leopard, 2009) — so macOS shows a 1TB drive as 1 TB. Windows still uses binary units (GiB) but labels them as GB, causing the apparent discrepancy. Linux distributions vary. Most storage devices, USB drives, and SSDs are marketed in SI units.
One petabyte (1 PB) is 1,000 terabytes or 1,000,000 gigabytes. To put it in perspective: 1 PB could store about 13.3 years of HD video, or all the text ever written by humans since the invention of writing. Major cloud providers store exabytes (1,000 PB) of data.

Source: https://worldcalculators.org/calculators/data-storage/
Markdown mirror of the HTML page. Prefer this URL for RAG; the interactive calculator still lives on the HTML page.