TooL Void
Zero API Β· Pure JavaScript Math

Convert Anything.
Instantly. Precisely.

12 categories, 100+ units β€” all with live results as you type. Temperature, length, weight, speed, data, and more.

12+
Categories
100+
Units
0ms
Lag

Start Converting

Select a category, enter a value β€” all units update instantly.

πŸ”
LIVE CONVERTER
πŸ“1 km = Γ· 1.609344 mi
Precision:
πŸ“Š ALL LENGTH UNITS
Nanometer999,999,999,999.9999nm
Micrometer1,000,000,000ΞΌm
Millimeter1,000,000mm
Centimeter100,000cm
Meter1,000m
Kilometer1km
Inch39,370.0787in
Foot3,280.8399ft
Yard1,093.6133yd
Mile0.6214mi
Nautical Mile0.54nmi
Light Year1.0570e-13ly

Built for Precision

Every detail engineered for accuracy, speed, and ease of use.

⚑

Instant Results

Every keystroke triggers a live recalculation. No buttons, no delays β€” values update as you type.

🌑️

12 Categories

Length, weight, temperature, speed, volume, area, energy, angle, fuel economy, digital storage, pressure, and time.

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All Units at Once

See your input converted into every unit of the category simultaneously in the "All Conversions" panel.

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Universal Search

Search any unit by name or symbol across all 12 categories β€” click a result to jump directly to it.

🎯

Precision Control

Choose 2, 4, 6, or 10 decimal places. Toggle scientific notation for very large or very small numbers.

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Copy Anywhere

One-click copy for any result β€” individual values, formulas, or full conversion strings from history.

How It Works

From input to accurate result in one step.

01
πŸ“

Choose Category

Select from 12 categories β€” length, weight, temperature, and more β€” using the tab bar.

02
⌨

Type Your Value

Enter any number. The converter updates all unit results in real time as you type.

03
πŸ”€

Pick Your Units

Choose any from/to unit pair from the dropdowns. Swap them with one click.

04
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Copy & Use

Copy the result, formula, or any value from the all-conversions panel instantly.

Who Uses It

Used daily across education, engineering, cooking, travel, and tech.

Students

Science & Math

Convert SI units, scientific notation, and physics quantities for homework and exams.

Engineers

Technical Specs

Switch between metric and imperial for pressure, energy, speed, and dimensional specs.

Developers

Data Sizes

Convert bits, bytes, KB, MB, GB, TB instantly when working with storage and bandwidth.

Cooks

Recipe Scaling

Convert teaspoons, tablespoons, cups, liters, and milliliters for any recipe or serving size.

Travelers

On the Road

Convert km to miles, Celsius to Fahrenheit, liters to gallons β€” all offline, instantly.

Scientists

Precision Work

Handle nanometers, electronvolts, light years, and pascals with full scientific notation support.

Frequently Asked

Everything about Unit Converter.

Are all conversions accurate?βŒ„
Yes. All conversions use precise multiplication factors stored directly in the source code. Temperature uses exact formulas (no rounding in the math). Results are formatted to your selected decimal precision.
Does it work offline?βŒ„
Completely. Unit Converter is 100% client-side JavaScript β€” no API calls, no server requests. It works entirely in your browser, even without an internet connection.
Why are some temperature results different from other converters?βŒ„
Scales like Delisle, Newton, RΓ©aumur, and RΓΈmer are historically accurate but rarely used today. Our formulas match the original definitions. Celsius, Fahrenheit, and Kelvin follow standard scientific conventions.
How do I convert multiple units at once?βŒ„
The "All Conversions" panel on the right shows your input value converted into every unit in the current category simultaneously β€” no extra clicks needed.
What is scientific notation mode?βŒ„
Toggle "Sci" to display results in scientific notation (e.g., 1.5 Γ— 10⁢). Useful for very large or very small values like nanometers, light years, or electronvolts.
Is my conversion history saved?βŒ„
Yes β€” your last 15 conversions are saved to localStorage and persist across sessions. You can see them in the history section below the converter.
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