Unit Converter

Convert between 80+ units across 10 categories. Instant bidirectional conversion with a full reference table.

Last reviewed: June 2026

Reviewed by Shannon Patterson, software engineer · last updated June 2026

New to this tool? Click here for instructions

Value

Result

From Unit

To Unit

Select a category and enter a value to convert.

All Units Reference Table

Unit	Value in Base Unit	Equivalent

How to Use the Unit Converter

The Unit Converter handles 80+ units across length, mass, temperature, volume, area, speed, time, data size, pressure, and energy. Results update instantly as you change a value, category, or unit.

Pick a category from the chips above the inputs.
Enter a value in the left field, then choose the source and target units.
Read the result in the right field, or type into the right field for reverse conversion.
Use the swap button when you want to flip the selected source and target units.

When to Use the Tool in Real Workflows

Use it for quick engineering checks, travel and cooking conversions, pressure and energy references, CSS or device-size estimates, data-size comparisons, and sanity checks before copying a value into a ticket, spreadsheet, or calculator.

How It Works

Each category has a base unit. The tool converts the source value to that base unit, then converts from the base unit to the target unit. Temperature scales use offset formulas instead of simple multiplication. The reference table below the converter is rebuilt from the same local constants, and no conversion request is sent to an external service.

For standards background, see NIST's SI overview, SI prefix table, and unit reference.

Tips, Edge Cases, or Limitations

Use the Data category for binary-style byte units; use the dedicated Byte Calculator when you need side-by-side binary and SI tables.
Temperature conversions are not proportional. Swapping Celsius and Fahrenheit changes both scale and offset.
Rounded display values are meant for practical use; keep extra precision when doing regulated calculations.
Some historical or domain-specific units vary by jurisdiction. Check the governing standard before using them in legal or safety-critical work.

Frequently Asked Questions

Select a category, enter a value, choose the source and target units, and the result will be displayed instantly.

Temperature conversion uses offset formulas. The most common scales are Celsius, Fahrenheit, and Kelvin. Kelvin starts at absolute zero (-273.15°C).

Binary prefixes (1 KB = 1,024 bytes) are standard in operating systems, while storage manufacturers often use SI prefixes (1 KB = 1,000 bytes).

The converter supports 80+ units across 10 categories.

The converter uses exact constants where the unit is defined exactly and common accepted constants elsewhere. It is useful for everyday engineering and reference work, but regulated scientific, legal, or medical decisions should be checked against the controlling standard.

Example walk-through

Convert inches to millimetres

Step 1. Leave the category set to Length.

Step 2. Click Try Example. The tool enters 1, selects Inch as the source unit, and selects Millimetre as the target unit.

Step 3. The browser converts the inch value to metres, then converts metres to millimetres.

1 in x 0.0254 m/in = 0.0254 m
0.0254 m / 0.001 m/mm = 25.4 mm

Step 4. The result field shows 25.4 and the status bar confirms 1 in = 25.4 mm.