Do I need to install software or create an account?

No. Everything runs in your web browser on Windows, Mac, Android and iPhone – there is nothing to download, nothing to install and no account to create.

Convertisseurs d’unités

Convertisseurs d'unités en ligne gratuits pour la longueur, le poids, la température, la surface, le volume, la vitesse, le temps, les octets, la pression, la puissance et le couple. Précis et instantané.

Convertisseurs d’unités gratuits en ligne – Métrique et impérial

🧰 12 free tools
💸 100% free
🔓 Aucune inscription
📱 Fonctionne sur tout appareil
🔒 Secure HTTPS

Unit converters change values between metric, imperial and other units using standard conversion factors – ideal for homework, travel, cooking and engineering.

All free unit converters on pdfseotools.com

All 12 Free Unit Converters

▦ All tools☰ Compare⭐ Featured

Tool	What it does	Input / Best for
Convertisseur de puissance	Convert power units online instantly with our free power converter	value → converted value
Convertisseur de poids	Convert weight and mass units online instantly with our free weight converter	value → converted value
Convertisseur de température	Convert temperature units online instantly with our free temperature converter	value → converted value
Convertisseur de tension	Convert electric voltage units online instantly with our free voltage converter	value → converted value
Convertisseur de surface	Convert area units online instantly with our free area converter	value → converted value
Convertisseur de longueur	Convert length and distance units online instantly with our free length converter	value → converted value
Convertisseur d’octets	Convert digital storage units online instantly with our free byte converter	value → converted value
Convertisseur de temps	Convert time units online instantly with our free time converter	value → converted value
Convertisseur de pression	Convert pressure units online instantly with our free pressure converter	value → converted value
Convertisseur de vitesse	Convert speed units online instantly with our free speed converter	value → converted value
Convertisseur de volume	Convert volume units online instantly with our free volume converter	value → converted value
Convertisseur de couple	Convert torque units online instantly with our free torque converter	value → converted value

Convertisseur de puissance

The Power Converter changes a power value from one unit to another using standard conversion factors. It removes manual calculation errors and works for both everyday and technical tasks.

Open Power Converter →

Convertisseur de poids

The Weight Converter changes a weight and mass value from one unit to another using standard conversion factors. It removes manual calculation errors and works for both everyday and technical tasks.

Open Weight Converter →

Convertisseur de température

The Temperature Converter changes a temperature value from one unit to another using standard conversion factors. It removes manual calculation errors and works for both everyday and technical tasks.

Open Temperature Converter →

Convertisseur de tension

The Voltage Converter changes a electric voltage value from one unit to another using standard conversion factors. It removes manual calculation errors and works for both everyday and technical tasks.

Open Voltage Converter →

How to Use Our Unit Converters

Enter the value you want to convert.
Choisissez l'unité à convertir.
Choisissez l'unité dans laquelle vous souhaitez convertir.
See the converted value instantly and copy it.

Unit Converters – Quick Reference

From	To	Multiply by
1 inch	centimetres	2.54
1 foot	centimetres	30.48
1 mile	kilometres	1.609344
1 kilogram	pounds	2.20462
1 US gallon	litres	3.78541
°C to °F	°F	× 9/5 + 32

Why Use Our Unit Converters?

Many units Covers metric, imperial and other commonly used units.
Precise conversion Uses internationally accepted conversion factors.
Instant results Values are converted as soon as you submit.
Free and unlimited Convert as many values as you like with the tool.
Mobile ready Works smoothly on phones, tablets and desktops.
Student friendly Ideal for homework, engineering and everyday tasks.

Tips for Using Unit Converters

Check that you selected the correct 'from' and 'to' units.
For scientific work keep extra decimal places and round at the end.
Remember that some units share names across systems (for example US and UK gallons).
Bookmark the page for quick daily conversions.

Unit Converters – Worked Example

Example: a recipe asks for 2 cups of milk and your jug shows millilitres. One US cup is about 236.6 ml, so 2 cups is roughly 473 ml. For temperature, 180 °C is 180 × 9/5 + 32 = 356 °F.

Unit Converters Glossary

Metric system: Decimal-based units such as metres, kilograms and litres.
Imperial units: Units such as inches, feet, pounds and gallons.
Conversion factor: The number you multiply by to change one unit into another.
Base unit: The reference unit a converter uses internally, such as the metre for length.
Significant figures: The meaningful digits in a measured value.

Helpful Guides for Unit Converters

Questions fréquentes

Are these unit converters free?

Yes. Every tool in this category is free to use on pdfseotools.com with no sign-up.

Do the tools work on mobile?

Yes. They work in any modern browser on Android, iPhone, Windows and Mac.

Is my data safe?

Yes. Connections use HTTPS and uploaded files are removed after processing.

Dois-je installer un logiciel ou créer un compte ?

Non. Tout s'exécute dans votre navigateur web sur Windows, Mac, Android et iPhone – rien à télécharger, rien à installer et aucun compte à créer.

Is there a limit on how often I can use these tools?

You can use the tools as often as you need for normal everyday tasks. Very large files or extreme usage may be limited to keep the service fast for everyone.

Where can I find more free tools?

Open the menu or the categories on pdfseotools.com to browse 150+ free tools for PDFs, images, text, SEO and development.