Length and volume across metric and imperial units

Value

Conversions use exact international factors (1 in = 25.4 mm; 1 US gal = 3.785411784 L).

Converted values

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Click any row to copy its value.


About Dimension Converter

The dimension converter handles length and volume conversions across metric and imperial units in one place. Pick the Length tab for millimeters through miles, or the Volume tab for milliliters through cubic yards and both US and imperial gallons; enter a value and its unit, and a full table of equivalents appears.

All conversions use the exact international factors — 1 inch is defined as exactly 25.4 mm, and 1 US gallon as exactly 3.785411784 liters — so the results are as precise as the definitions themselves. Every row in the results table is click-to-copy, which makes moving values into a spreadsheet, CAD file, or email painless.

It is the everyday tool for construction and engineering work that straddles unit systems: checking an imperial drawing against metric stock, converting cubic meters of concrete to cubic yards for a US supplier, or translating gallons to liters. Free, instant, and entirely in your browser.

How to use Dimension Converter

  1. Choose the Length or Volume tab.
  2. Enter your value and select its unit.
  3. Read the full table of converted values in every other unit.
  4. Click any row to copy that value to the clipboard.

Frequently asked questions

Exactly 25.4 mm — the inch has been defined that way internationally since 1959, so inch-to-metric conversions carry no rounding error at all. A foot is therefore exactly 304.8 mm.

A US gallon is exactly 3.785411784 L, while an imperial (UK) gallon is 4.54609 L — about 20% larger. The converter lists both separately so fuel, paint, and liquid volumes never get mixed up.

Multiply by about 1.30795: 5 m³ of concrete is roughly 6.54 yd³. Enter the value under Volume in cubic meters and read the cubic-yard row — or click it to copy.

Yes — that is the point of the results table. One entered value is shown simultaneously in every supported unit, metric and imperial alike, so a length typed in feet is instantly readable in millimeters, meters, and miles.

The factors are the exact legal definitions, so accuracy is limited only by the digits displayed. For engineering documents, copy the value and keep as many significant figures as your specification requires.

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