SI and metric prefix converter

Convert between SI metric prefixes such as giga, mega, kilo, milli, micro and nano, from quecto (10⁻³⁰) to quetta (10³⁰), including the 2022 additions.

Mis à jour 28 septembre 2026Exemples vérifiés : 5

Valeur

Vers

Unit symbol (facultatif)

Only used for labels, e.g. m, g, Hz, W

Essayer

Valeur convertie

MHz

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

Conversion: 2.4 GHz = 2,400 MHz
Shift in powers of ten: 3

Going from giga (10⁹) to mega (10⁶) moves the decimal point 3 places to the right: 2.4 GHz = 2,400 MHz.

Where the two prefixes sit on the powers of ten

2.4 GHz with every prefix Lignes : 25

Prefix	Factor	Valeur
quetta (Q)	10³⁰	2.4 × 10⁻²¹ QHz
ronna (R)	10²⁷	2.4 × 10⁻¹⁸ RHz
yotta (Y)	10²⁴	2.4 × 10⁻¹⁵ YHz
zetta (Z)	10²¹	2.4 × 10⁻¹² ZHz
exa (E)	10¹⁸	2.4 × 10⁻⁹ EHz
peta (P)	10¹⁵	0.0000024 PHz
tera (T)	10¹²	0.0024 THz
giga (G)	10⁹	2.4 GHz
mega (M)	10⁶	2,400 MHz
kilo (k)	10³	2,400,000 kHz
hecto (h)	10²	24,000,000 hHz
deca (da)	10¹	240,000,000 daHz
none	10⁰	2,400,000,000 Hz
deci (d)	10⁻¹	24,000,000,000 dHz
centi (c)	10⁻²	240,000,000,000 cHz
milli (m)	10⁻³	2,400,000,000,000 mHz
micro (µ)	10⁻⁶	2.4 × 10¹⁵ µHz
nano (n)	10⁻⁹	2.4 × 10¹⁸ nHz
pico (p)	10⁻¹²	2.4 × 10²¹ pHz
femto (f)	10⁻¹⁵	2.4 × 10²⁴ fHz
atto (a)	10⁻¹⁸	2.4 × 10²⁷ aHz
zepto (z)	10⁻²¹	2.4 × 10³⁰ zHz
yocto (y)	10⁻²⁴	2.4 × 10³³ yHz
ronto (r)	10⁻²⁷	2.4 × 10³⁶ rHz
quecto (q)	10⁻³⁰	2.4 × 10³⁹ qHz

Comment le calcul est effectué S

Prefix powers
$\text{giga} = 10^{9},\quad \text{mega} = 10^{6}$
SI Brochure Table 7; ronna, quetta, ronto and quecto since 2022.
Shift the power of ten
$2.4 \times 10^{9 - 6} = 2.4 \times 10^{3} = 2{,}400\ \text{MHz}$
Powers of ten are exact, so the result has the same digits as the value you entered.

À propos de SI and metric prefix converter

An SI prefix multiplies a unit by a power of ten: kilo is 10³, mega 10⁶, milli 10⁻³ and nano 10⁻⁹. Converting between two prefixes multiplies the value by 10 raised to the difference of their exponents, which moves the decimal point without changing any digits. The converter covers all 24 SI prefixes, from quecto (10⁻³⁰) to quetta (10³⁰).

Engineers and students use it to move between scales of one unit. The default turns the 2.4 GHz Wi-Fi band into 2,400 MHz, a shift of three powers of ten. The unit symbol field only labels the result, so the same conversion works for metres, grams, hertz or watts.

Two BIPM rules apply to every prefix: prefixes are never combined (write nm, not mµm), and because the kilogram already carries one, prefixes attach to the gram: 1 mg, not 1 µkg.

Exemples détaillés

2.4 GHz in MHz

Valeur: 2.4
De: giga (G, 10⁹)
Vers: mega (M, 10⁶)
Unit symbol: Hz

Valeur convertie: 2,400 MHz
Conversion: 2.4 GHz = 2,400 MHz
Shift in powers of ten: 3

Source de vérification : giga = 10⁹, mega = 10⁶ (SI Brochure Table 7): 2.4 × 10³

1 km in m

Valeur: 1
De: kilo (k, 10³)
Vers: none (10⁰)
Unit symbol: m

Valeur convertie: 1,000 m

Source de vérification : kilo = 10³

1 quetta in yotta (2022 prefix)

Valeur: 1
De: quetta (Q, 10³⁰)
Vers: yotta (Y, 10²⁴)
Unit symbol: g

Valeur convertie: 1,000,000 Yg
Shift in powers of ten: 6

Source de vérification : quetta = 10³⁰ (CGPM 2022), yotta = 10²⁴

Smallest to largest: quecto to quetta

Valeur: 1
De: quecto (q, 10⁻³⁰)
Vers: quetta (Q, 10³⁰)
Unit symbol: g

Shift in powers of ten: -60
Valeur convertie: 1 × 10⁻⁶⁰ Qg

Source de vérification : 10⁻³⁰ / 10³⁰ = 10⁻⁶⁰

Questions

What are the SI prefixes in order?

There are 24. From largest: quetta (Q, 10³⁰), ronna (R, 10²⁷), yotta (Y, 10²⁴), zetta (Z), exa (E), peta (P), tera (T), giga (G), mega (M), kilo (k, 10³), hecto (h, 10²) and deca (da, 10¹). Then the submultiples: deci (d), centi (c), milli (m, 10⁻³), micro (µ), nano (n), pico (p), femto (f), atto (a), zepto (z), yocto (y), ronto (r) and quecto (q, 10⁻³⁰).

What are the newest SI prefixes?

Ronna (R, 10²⁷), quetta (Q, 10³⁰), ronto (r, 10⁻²⁷) and quecto (q, 10⁻³⁰), adopted by the 27th General Conference on Weights and Measures (CGPM) in November 2022. They were the first additions since zetta, yotta, zepto and yocto in 1991. On the new scale the Earth's mass, about 5.97 × 10²⁴ kg, is roughly 6 ronnagrams.

How do I convert between metric prefixes?

Subtract the exponents and move the decimal point that many places. From giga (10⁹) to mega (10⁶) is 9 − 6 = 3 places to the right, so 2.4 GHz = 2,400 MHz; from micro (10⁻⁶) to nano (10⁻⁹) is also 3 places, so 5 µs = 5,000 ns. Moving to a larger prefix shifts the point left: 1,500 m = 1.5 km.

Why is kilo a lowercase k but mega an uppercase M?

The SI writes the symbols for multiples from mega (M, 10⁶) upward in capitals, while kilo (k), hecto (h), deca (da) and every submultiple are lowercase. The case changes the value: 1 MW (megawatt) is 10⁹ times 1 mW (milliwatt). Writing K for kilo is wrong in the SI, because K is the symbol for the kelvin.

Does kilo mean 1,000 or 1,024 in computing?

In the SI, kilo always means exactly 1,000, so 1 kbit = 1,000 bits and 1 GB = 10⁹ bytes (NIST). For powers of two the IEC approved binary prefixes in December 1998: 1 KiB (kibibyte) = 1,024 bytes and 1 GiB = 2³⁰ = 1,073,741,824 bytes. The gap grows with size, which is why a 1 TB drive shows about 931 GiB.

Quelle est la précision de « SI and metric prefix converter » ?

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, « 2.4 GHz in MHz » est vérifié à l’aide de giga = 10⁹, mega = 10⁶ (SI Brochure Table 7): 2.4 × 10³.

D’où vient cette méthode ?

BIPM — The International System of Units (SI Brochure, 9th ed.), Table 7: SI prefixes; BIPM — CGPM 2022 Resolution 3: ronna, quetta, ronto, quecto.

À propos de ce calculateur

x_{\text{to}} = x_{\text{from}} \times 10^{\,e_{\text{from}} - e_{\text{to}}}

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.