Convertisseur de stockage de données

Convertissez GB en MB, TB en GB et GiB en GB en distinguant les préfixes décimaux (kB, MB, GB, TB) et binaires (KiB, MiB, GiB, TiB), ainsi que bits et octets.

Mis à jour 29 septembre 2026Exemples vérifiés : 5

Valeur

Un nombre dans l’unité de départ, ou accompagné de sa propre unité

Vers

Essayer

Valeur convertie

Chiffres significatifs : 12 ; Au plus proche, égalités en s’éloignant de zéro

Conversion: 1 GiB = 1,073.741824 MB
Facteur de conversion: 1,073.741824
Exactitude: Exact

1 GiB vaut exactement 1,073.741824 MB.

Écart entre chaque préfixe binaire et son équivalent décimal

1 GiB dans chaque unité de Stockage de données Lignes : 25

Unité	Valeur	Définition
bit	8,589,934,592	Unité de base
nibble	2,147,483,648	1 nibble = 4 bit, exact
byte (B)	1,073,741,824	1 B = 8 bit, exact
kilobyte (kB)	1,073,741.824	1 kB = 8,000 bit, exact
mégaoctet (MB)	1,073.741824	1 MB = 8,000,000 bit, exact
gigaoctet (GB)	1.073741824	1 GB = 8,000,000,000 bit, exact
téraoctet (TB)	0.001073741824	1 TB = 8,000,000,000,000 bit, exact
petabyte (PB)	0.000001073741824	1 PB = 8 × 10¹⁵ bit, exact
exabyte (EB)	1.073741824 × 10⁻⁹	1 EB = 8 × 10¹⁸ bit, exact
zettabyte (ZB)	1.073741824 × 10⁻¹²	1 ZB = 8 × 10²¹ bit, exact
yottabyte (YB)	1.073741824 × 10⁻¹⁵	1 YB = 8 × 10²⁴ bit, exact
kibibyte (KiB)	1,048,576	1 KiB = 8,192 bit, exact
mebibyte (MiB)	1,024	1 MiB = 8,388,608 bit, exact
gibibyte (GiB)	1	1 GiB = 8,589,934,592 bit, exact
tebibyte (TiB)	0.0009765625	1 TiB = 8,796,093,022,208 bit, exact
pebibyte (PiB)	9.536743 × 10⁻⁷	1 PiB = 9.007199254740992 × 10¹⁵ bit, exact
exbibyte (EiB)	9.313226 × 10⁻¹⁰	1 EiB = 9.223372036854775808 × 10¹⁸ bit, exact
zebibyte (ZiB)	9.094947 × 10⁻¹³	1 ZiB = 9.4447329657392904274 × 10²¹ bit, exact
yobibyte (YiB)	8.881784197 × 10⁻¹⁶	1 YiB = 9.6714065569170333976 × 10²⁴ bit, exact
kilobit (kbit)	8,589,934.592	1 kbit = 1,000 bit, exact
megabit (Mbit)	8,589.934592	1 Mbit = 1,000,000 bit, exact
gigabit (Gbit)	8.589934592	1 Gbit = 1,000,000,000 bit, exact
terabit (Tbit)	0.008589934592	1 Tbit = 1,000,000,000,000 bit, exact
kibibit (Kibit)	8,388,608	1 Kibit = 1,024 bit, exact
mebibit (Mibit)	8,192	1 Mibit = 1,048,576 bit, exact

Comment le calcul est effectué S

Convertir gibibyte en bit
$1\ \text{GiB} \times 8{,}589{,}934{,}592\ \tfrac{\text{bit}}{\text{GiB}} = 8{,}589{,}934{,}592\ \text{bit}$
1 GiB = 8,589,934,592 bit, exact
Convertir bit en mégaoctet
$8{,}589{,}934{,}592\ \text{bit} \div 8{,}000{,}000\ \tfrac{\text{bit}}{\text{MB}} = 1{,}073.741824\ \text{MB}$
1 MB = 8,000,000 bit, exact
Facteur combiné
$1\ \text{GiB} = \frac{8{,}589{,}934{,}592}{8{,}000{,}000}\ \text{MB} = 1{,}073.741824\ \text{MB}$
Les deux unités sont définies exactement et la valeur convertie est une décimale finie : chaque chiffre affiché est donc exact.

À propos de Convertisseur de stockage de données

Data sizes use two sets of prefixes. The decimal ones follow the SI: 1 kB = 1,000 bytes, 1 MB = 10⁶ and 1 GB = 10⁹ bytes. The binary ones, approved by the IEC in December 1998 and now part of IEC 80000-13, step by 1,024: 1 KiB = 1,024 bytes, 1 MiB = 2²⁰ and 1 GiB = 2³⁰ bytes. A byte is 8 bits, and every conversion between these units is exact.

The default converts 1 GiB to 1,073.741824 MB. The same gap explains why a new drive looks smaller: a 1 TB drive holds 10¹² bytes, which software counting in binary units shows as 931.32 GiB, often labelled “931 GB”.

The gap grows with each prefix: 2.4% at kilo, 7.37% at giga, 9.95% at tera and 20.9% at yotta. Memory chips come in powers of two, so RAM sizes are binary even when written GB, while drive makers and network speeds use decimal prefixes.

Exemples détaillés

1 GiB in MB

Valeur: 1 GiB
De: gibibyte (GiB)
Vers: megabyte (MB)

Valeur convertie: 1,073.741824 MB
Exactitude: Exact

Source de vérification : 2³⁰ bytes = 1,073,741,824 bytes (IEC 80000-13); ÷ 10⁶

A 1 TB drive in GiB

Valeur: 1 TB
De: terabyte (TB)
Vers: gibibyte (GiB)

Valeur convertie: 931.322574615 GiB

Source de vérification : 10¹² / 2³⁰ = 244140625/262144, a terminating decimal (Python fractions)

1 KiB in kB

Valeur: 1 KiB
De: kibibyte (KiB)
Vers: kilobyte (kB)

Valeur convertie: 1.024 kB

Source de vérification : 1024 bytes / 1000 bytes

Largest gap: 1 YiB in YB

Valeur: 1 YiB
De: yobibyte (YiB)
Vers: yottabyte (YB)

Valeur convertie: 1.20892581961 YB

Source de vérification : 2⁸⁰ / 10²⁴ = 1.208925819614629174706176 exactly (Python fractions)

Questions

Why does my 1 TB drive show only 931 GB?

Because the maker and the operating system count differently. The drive's 1 TB is 10¹² bytes; Windows divides by 2³⁰ and shows 931.32 while labelling it GB. Nothing is missing, since 10¹² ÷ 1,073,741,824 = 931.32; formatting and recovery partitions take a little more. macOS has counted in decimal since OS X 10.6 and shows the same drive as 1 TB.

Is 1 GB 1,000 MB or 1,024 MB?

Under the SI and IEC 80000-13, 1 GB is exactly 1,000 MB (10⁹ bytes), and the binary unit is 1 GiB = 1,024 MiB (2³⁰ bytes). Drive makers and macOS use the decimal meaning; RAM and Windows use the binary one while writing GB. The “1.44 MB” floppy disk mixed the two: 1,440 × 1,024 bytes.

How many bits are in a byte?

Eight. IEC 80000-13 defines the byte as 8 bits, also called an octet. File sizes are counted in bytes (B) and network speeds in bits per second (bit/s), so a 100 Mbit/s connection moves at most 12.5 MB per second; a capital B marks bytes.

What is a GiB?

A gibibyte, 2³⁰ = 1,073,741,824 bytes. The IEC created the binary prefixes kibi, mebi, gibi and tebi so that kilo, mega and giga could keep their SI meanings of 10³, 10⁶ and 10⁹. Many Linux tools and technical specifications use GiB; Windows shows the same quantity labelled GB.

How many GB are in 1 TB?

1,000 GB in decimal units, which is how drives are sold. In binary units 1 TiB is 1,024 GiB, and a decimal 1 TB is 931.32 GiB. The converter keeps TB, TiB, GB and GiB separate, so you can see that 1 TiB is 1,099.51 GB, about 10% more than 1 TB.

Quelle est la précision de « Convertisseur de stockage de données » ?

La précision dépend de vos données et des hypothèses de la méthode. Le calcul décimal utilise 50 chiffres significatifs, mais les estimations, méthodes numériques et données sources peuvent être moins précises ; l’arrondi affiché ne supprime pas ces limites. Exemples résolus vérifiés à partir de sources indépendantes : 5. Par exemple, « 1 GiB in MB » est vérifié à l’aide de 2³⁰ bytes = 1,073,741,824 bytes (IEC 80000-13); ÷ 10⁶.

D’où vient cette méthode ?

NIST SP 811 (2008), Guide for the Use of the SI, Appendix B — conversion factors; NIST Handbook 44, Appendix C — General tables of units of measurement; NIST — Prefixes for binary multiples (IEC 80000-13).

À propos de ce calculateur

\begin{gathered} x_{\text{to}} = x_{\text{from}} \times \dfrac{f_{\text{from}}}{f_{\text{to}}} \\ f = \text{one unit expressed in } \text{bit} \end{gathered}

Sources

Vérifié avec les références

Ce calculateur comprend 5 exemples résolus dont les réponses proviennent de sources indépendantes. Ils font partie de la suite de tests et peuvent aussi être exécutés ici.