Which units does the converter support?

Length, weight, temperature, volume, speed, area, time, data size, fuel economy, and energy — the most common everyday units plus several engineering/scientific ones.

Does it handle compound units like km/h?

Yes — the Speed tab converts km/h, mph, knots, m/s, and ft/s directly between each other.

How accurate are the conversion factors?

Converter uses SI-base conversion factors to 10 significant digits. For legal, scientific, or engineering work, always verify against the authoritative source for your domain.

Can I bookmark a specific conversion?

Yes — the URL updates as you change inputs, so you can bookmark or share a link that pre-fills a specific value and unit pair.

What's the difference between US gallons, UK (imperial) gallons, and liters?

1 US gallon = 3.785 liters = 0.832 imperial gallons. 1 imperial (UK) gallon = 4.546 liters = 1.201 US gallons — a notable 20% difference. UK pints are also larger (568ml vs. US 473ml). When converting recipes from US to UK or vice versa, this 20% gap can wreck baking measurements. The metric system avoids these dual-gallon problems entirely; cooking in liters and milliliters is universally portable.

How do I convert between metric and US fabric sizes?

Length: 1 yard = 0.9144 meters; 1 meter = 1.0936 yards. Fabric is typically sold in fractions of yards in the US (1/8 yard = ~11cm), in 0.1m increments in metric countries. Width: 'wide' US fabric is 60 inches (152cm); EU fabric is often 140cm or 150cm wide. When ordering from international shops, always confirm both length and width — a '1 meter' purchase could be 140cm, 150cm, or 152cm wide depending on the bolt.

Unit Converters · Free tool

Unit Converter

Convert length, weight, volume, area, speed, energy, and more with this free online tool. All common units in one place, no registration needed.

Updated June 2026

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What it does

A free unit converter for length, weight, volume, and area — the everyday conversions that come up constantly. Meters to feet, pounds to kilograms, gallons to liters, acres to hectares. Runs in your browser with live updates as you type.

Conversions are a staple of cross-country recipes, travel planning, international shipping, and DIY projects. This tool covers the main categories you’ll hit 99% of the time; specialized conversions (cooking temperatures, fuel economy) are handled by our temperature converter and category-specific tools.

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Paste this snippet into any page. Loads on-demand (lazy), no tracking scripts, and sized to most dashboards. Replace the height to fit your layout.

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How to use it

Pick a category: length, weight, volume, or area.
Enter a value in the From field.
Pick the From and To units.
Read the converted value — updates live as you type.

When to use this tool

Recipe conversion (US cups to grams, Fahrenheit to Celsius for international cookbooks).
International shopping where measurements differ (UK fabric vs US, EU shoe sizes).
DIY projects where dimensions cross unit systems (lumber sold in feet, hardware in mm).
School and homework assignments requiring specific units.

When not to use it

Currency conversion — use the currency converter (live exchange rates).
Time zone math — use the time zone converter.
Specialized scientific conversion (cgs to SI, astronomical units) — use category-specific scientific tools.

Common use cases

Converting 425°F to 218°C for a US recipe in a metric kitchen.
Switching 175cm to 5'9" for a US driver's license application.
Translating 200 grams of butter to 7 ounces for an American cookbook.
Quick check that a 50kg checked-bag limit is about 110 lbs.

Frequently asked questions

Which units does the converter support?: Length, weight, temperature, volume, speed, area, time, data size, fuel economy, and energy — the most common everyday units plus several engineering/scientific ones.
Does it handle compound units like km/h?: Yes — the Speed tab converts km/h, mph, knots, m/s, and ft/s directly between each other.
How accurate are the conversion factors?: Converter uses SI-base conversion factors to 10 significant digits. For legal, scientific, or engineering work, always verify against the authoritative source for your domain.
Can I bookmark a specific conversion?: Yes — the URL updates as you change inputs, so you can bookmark or share a link that pre-fills a specific value and unit pair.
What's the difference between US gallons, UK (imperial) gallons, and liters?: 1 US gallon = 3.785 liters = 0.832 imperial gallons. 1 imperial (UK) gallon = 4.546 liters = 1.201 US gallons — a notable 20% difference. UK pints are also larger (568ml vs. US 473ml). When converting recipes from US to UK or vice versa, this 20% gap can wreck baking measurements. The metric system avoids these dual-gallon problems entirely; cooking in liters and milliliters is universally portable.
How do I convert between metric and US fabric sizes?: Length: 1 yard = 0.9144 meters; 1 meter = 1.0936 yards. Fabric is typically sold in fractions of yards in the US (1/8 yard = ~11cm), in 0.1m increments in metric countries. Width: 'wide' US fabric is 60 inches (152cm); EU fabric is often 140cm or 150cm wide. When ordering from international shops, always confirm both length and width — a '1 meter' purchase could be 140cm, 150cm, or 152cm wide depending on the bolt.

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