Volume Converter
From a millilitre to a gallon, including the often-overlooked detail that a US gallon and a UK gallon aren't the same size — a genuinely common source of recipe and fuel-economy confusion between countries.
Inputs
Result
0.000001 Cubic metre
1 Millilitre = 0.000001 Cubic metre
How it works
value × (factor of source unit) ÷ (factor of target unit)
- 1Convert to base unit: 1 × 0.001 = 0.001
- 2Convert to target unit: 0.001 ÷ 1000 = 0.000001
How the volume converter works
All units convert through litres as the base — 1 Cubic metre = 1,000 L, 1 Gallon (US) = 3.785412 L, 1 Gallon (UK) = 4.54609 L, 1 Cup (US) = 0.2365882 L.
Worked example: 10 US gallons to litres, compared with UK gallons
- 10 × 3.785412 = 37.85412 litres (US gallons).
- The same 10 UK gallons instead: 10 × 4.54609 = 45.4609 litres — about 20% more volume for the same nominal '10 gallons', purely from the definition difference.
Common mistakes to avoid
Assuming a US gallon and UK (imperial) gallon are interchangeable
A UK gallon is about 20% larger than a US gallon — this matters significantly for fuel economy comparisons (miles per gallon means something different in each country) and any recipe or industrial specification crossing between US and UK conventions.
Confusing a US cup with a metric or Commonwealth 'cup'
As with the Cooking Converter, the US customary cup (236.5882 ml) differs slightly from a metric cup sometimes informally treated as 250 ml — a small but real difference for precision baking.
Frequently asked questions
Why do the US and UK use different gallon sizes?
They stem from different historical definitions that were never fully unified between the US and Britain — the US retained an older wine-gallon-based definition while the UK adopted a different standard, and the two never converged.
How does this affect fuel economy figures between countries?
A car quoted as getting '40 MPG' in the UK is not directly comparable to '40 MPG' in the US, since the underlying gallon size differs — converting both to a common unit like litres per 100km is the only fair comparison.
What's the exact relationship between a litre and a cubic metre?
1 cubic metre = 1,000 litres exactly, since a litre is defined as exactly 1,000 cubic centimetres, and a cubic metre contains 100³ = 1,000,000 cubic centimetres.
How is this related to the Fuel Economy Converter?
That tool handles the combined distance-and-volume conversion (km/l, MPG, L/100km) directly; this tool handles pure volume-to-volume conversion on its own, useful as a building block for many other calculations.
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