Litres and US liquid gallons
A US liquid gallon is exactly 3.785411784 litres. Dividing litres by that quantity, or multiplying by 0.2641720524, gives US gallons. This is a capacity conversion: it says how much space a liquid would occupy under the stated unit system, not how much the liquid weighs.
Fuel-purchase arithmetic
Ten litres equals 2.64 US gallons. A 45-litre refill is about 11.89 US gallons, which is useful when comparing a receipt with a vehicle specification written in US units. The pump total may still differ slightly because the nozzle stops at a practical fill level and the fuel temperature changes volume.
Choose the gallon before comparing
The Imperial gallon used in the United Kingdom is 4.54609 litres, substantially larger than the US gallon. A fuel-economy figure expressed per Imperial gallon cannot be compared directly with a US-gallon price or consumption rate. Read the country convention on the pump, manual, or recipe before applying a factor.
What capacity conversion cannot supply
This result does not turn litres into kilograms, tell how full an irregular tank is, or account for expansion, foam, headspace, and calibration. Tank geometry and liquid density require their own data.
Container markings are practical limits
A jug line at 1 litre is often intended for kitchen use, not a laboratory calibration. Ten litres may convert cleanly to 2.64 US gallons, yet a container filled to its rim may spill when moved and a tank's usable capacity can be below its geometric volume. For a recipe, use the measuring convention it names; for fuel or chemicals, use the instrument and safety margin appropriate to the material.
A direction check for gallons
A US gallon is larger than a litre, so the gallon count is smaller than the litre count: 10 litres equals about 2.64 US gallons. If a record says 10 litres equals 37.85 gallons, it has likely multiplied by the litres-per-gallon number instead of dividing. Reverse-converting 2.64 gallons gives roughly 10 litres after normal display rounding.
State the liquid basis
When a quantity supports a purchase or mixture, identify whether it was read from a bottle, a calibrated tank, or a calculated container shape. Those origins carry different uncertainty.