Accurate volume conversion between litres (L) and Australian gallons (imperial gallons) — and back
Convert litres to Australian gallons instantly using the exact factor of 4.54609 L per AU gallon. Full multi-unit breakdown into AU gal, US gal, L, mL, m³, and ft³ — all in one free tool for 2026.
Professional volume conversion for Australian fuel, agriculture, water tanks, pool maintenance, and pre-metric historical references
Australia historically used the imperial gallon before metrication in the 1970s — and that imperial gallon is what is still referred to as the "Australian gallon" today. By exact definition, 1 Australian (imperial) gallon = 4.54609 litres, making it approximately 20% larger than the US gallon (3.78541 L). The exact factor 4.54609 is defined by international agreement and is perfectly precise — derived from the definition: 1 imperial gallon = 10 pounds of water at 62°F = 277.42 cubic inches = 4.54609 L. Australia completed metrication in 1974, replacing gallons with litres for all fuel, liquid, and volume measurements — but the AU gallon remains relevant for old tank ratings, agricultural equipment specs, and cross-reference with UK figures.
The Australian/imperial gallon and the US gallon are two completely different units despite sharing the name "gallon." 1 AU gallon = 4.54609 L vs 1 US gallon = 3.78541 L — a difference of about 20%. This means 10 AU gallons = 45.46 L, while 10 US gallons = 37.85 L. The distinction matters critically for: fuel economy comparisons (AU mpg vs US mpg), tank and equipment specifications imported from the US vs sourced locally, agricultural chemical dilution rates, and comparing old Australian records (pre-1974) with modern litre-based data. This converter clearly displays both AU and US gallon equivalents simultaneously so you never confuse the two.
Despite Australia's full metrication, the Australian (imperial) gallon still appears in several real-world contexts: Old farm equipment and tanks — pre-1974 machinery and tank ratings stamped in gallons; Imported UK products — British-origin agricultural chemicals, irrigation fittings, and plumbing components rated in imperial gallons; Fuel economy heritage records — classic car fuel consumption figures in miles per gallon (mpg); Marine and boating — some older vessel fuel tank capacities in AU gallons; New Zealand cross-reference — NZ also used imperial gallons pre-metrication; Brewing and distilling — traditional recipe archives in gallons; Pool and spa maintenance — some older Australian pool chemical dosing guides.
Select conversion direction, enter your volume value, and get instant multi-unit results including both AU and US gallons
The Australian gallon is identical to the imperial gallon — the traditional unit of volume used throughout the British Empire and its former territories. It is defined as exactly 4.54609 litres, a value that has been internationally agreed since 1985 (and was previously defined as 10 pounds of distilled water at 62°F/16.7°C under standard atmospheric pressure, which equals 277.4194 cubic inches = 4.54609 L). Australia adopted this unit from the British system during colonial administration, and it was used for all liquid and fuel measurements until the country completed metrication in the 1970s under the Australian Metric Conversion Board established in 1970.
The conversion factor 1 AU gallon = 4.54609 L is exact by definition — no decimal approximation is introduced at any precision level. Inversely, 1 litre = 1/4.54609 = 0.21996924… AU gallons, commonly rounded to 0.21997. The Australian gallon is larger than the US gallon (3.78541 L) by a factor of 4.54609/3.78541 ≈ 1.2009 — meaning the AU gallon is about 20% larger. It is also larger than the US dry gallon (4.40488 L). Critically, when comparing fuel economy figures in "miles per gallon": an Australian MPG figure uses more litres per gallon than a US MPG figure — so 30 AU mpg ≠ 30 US mpg; 30 AU mpg = 30 × 4.54609/3.78541 = 36.05 US mpg.
Example: 50 L ÷ 4.54609 = 10.998 AU gal | 20 AU gal × 4.54609 = 90.922 L
1 AU gal = 4.54609 L | 1 US gal = 3.78541 L | 1 AU gal = 1.20095 US gal | 1 AU gal = 8 pints | 1 AU gal = 160 fl oz (imperial)
To convert litres to Australian gallons, divide by 4.54609. To convert AU gallons back to litres, multiply by 4.54609. Here are three practical worked examples:
Input: 68 L (car fuel tank)
Formula: 68 ÷ 4.54609
= 14.958 AU gal
= typical modern car fuel tank
Input: 200 AU gal (old tank rating)
Formula: 200 × 4.54609
= 909.218 L
= common pre-metric tank size
Input: 1,000 L (pool volume fraction)
Formula: 1,000 ÷ 4.54609
= 219.969 AU gal
= dosing reference for old guide
L → AU gal (quick estimate): Divide litres by 4.5 for a fast approximation — error is less than 1%. Example: 90 L ÷ 4.5 = 20 AU gal (exact: 19.797 AU gal). AU gal → L (quick estimate): Multiply by 4.5 for a close result. Example: 10 AU gal × 4.5 = 45 L (exact: 45.461 L — error <1%). Precision method: Always use 4.54609 for technical, agricultural, or engineering calculations. Key benchmarks: 1 AU gal = 4.546 L; 10 AU gal = 45.461 L; 100 AU gal = 454.609 L; 1,000 AU gal = 4,546.09 L. AU vs US: Multiply US gallons by 1.20095 to get AU gallons; divide AU gallons by 1.20095 to get US gallons. Fuel economy: To convert AU mpg to L/100km: 282.48 ÷ mpg(AU) = L/100km. To convert US mpg to L/100km: 235.21 ÷ mpg(US) = L/100km.
Complete reference table from small containers through large tanks and pools, with AU gal, US gal, m³, and ft³ equivalents plus real-world context. Desktop shows the full table; mobile shows grouped cards.
| Litres (L) | AU Gallons (imp) | US Gallons | m³ | ft³ | Real-World Reference |
|---|---|---|---|---|---|
| 1 L | 0.21997 AU gal | 0.26417 | 0.001 | 0.03531 | 1 litre bottle |
| 4.546 L | 1.000 AU gal | 1.20095 | 0.004546 | 0.16054 | Exactly 1 AU gallon |
| 5 L | 1.0998 AU gal | 1.32086 | 0.005 | 0.17657 | Paint tin / jerrycan |
| 9.092 L | 2.000 AU gal | 2.40190 | 0.009092 | 0.32109 | Exactly 2 AU gallons |
| 10 L | 2.1997 AU gal | 2.64172 | 0.010 | 0.35315 | Large bucket |
| 20 L | 4.3994 AU gal | 5.28344 | 0.020 | 0.70629 | Fuel canister |
| 22.730 L | 5.000 AU gal | 6.00476 | 0.02273 | 0.80268 | Exactly 5 AU gallons |
| 45.461 L | 10.000 AU gal | 12.009 | 0.04546 | 1.6054 | Exactly 10 AU gallons |
| 50 L | 10.998 AU gal | 13.209 | 0.050 | 1.7657 | Large drum / cooler |
| 68 L | 14.958 AU gal | 17.963 | 0.068 | 2.401 | Typical car fuel tank |
| 90.922 L | 20.000 AU gal | 24.019 | 0.09092 | 3.2109 | Exactly 20 AU gallons |
| 100 L | 21.997 AU gal | 26.417 | 0.100 | 3.531 | Standard oil drum / aquarium |
| 136.38 L | 30.000 AU gal | 36.028 | 0.13638 | 4.816 | Exactly 30 AU gallons |
| 200 L | 43.994 AU gal | 52.834 | 0.200 | 7.063 | Standard 200 L drum |
| 227.30 L | 50.000 AU gal | 60.047 | 0.22730 | 8.027 | Exactly 50 AU gallons |
| 454.61 L | 100.000 AU gal | 120.095 | 0.45461 | 16.054 | Exactly 100 AU gallons |
| 500 L | 109.985 AU gal | 132.086 | 0.500 | 17.657 | Livestock water trough |
| 909.22 L | 200.000 AU gal | 240.19 | 0.90922 | 32.109 | Old pre-metric 200 gal tank |
| 1,000 L | 219.969 AU gal | 264.172 | 1.000 | 35.315 | 1 m³ / IBC tote / kilolitre |
| 1,136.5 L | 250.000 AU gal | 300.24 | 1.1365 | 40.135 | Exactly 250 AU gallons |
| 2,000 L | 439.938 AU gal | 528.34 | 2.000 | 70.629 | Small above-ground pool |
| 2,273.0 L | 500.000 AU gal | 600.47 | 2.273 | 80.27 | Exactly 500 AU gallons |
| 5,000 L | 1,099.85 AU gal | 1,320.86 | 5.000 | 176.57 | Large domestic water tank |
| 10,000 L | 2,199.69 AU gal | 2,641.72 | 10.000 | 353.15 | Small swimming pool |
🟢 Green = small / everyday | 🟧 Orange = household / medium industrial | 🔵 Blue = large / commercial
Australia used miles per gallon (mpg) for fuel economy before the 1970s, and the gallon in those figures is the imperial/AU gallon (4.54609 L). Converting between old mpg figures and modern L/100km requires this conversion. Formula: L/100km = 282.48 ÷ mpg (AU gallon). Example: a 1965 Holden rated at 30 mpg (AU) = 282.48 ÷ 30 = 9.42 L/100km. Classic car enthusiasts, automotive historians, and motoring journalists comparing vintage vs. modern fuel efficiency regularly need to convert between old AU mpg figures and the current Australian metric standard of litres per 100 kilometres (L/100km).
Pre-1974 Australian farm water tanks, stock troughs, spray equipment, and irrigation systems were all rated in imperial (AU) gallons. A "500-gallon tank" on an old Australian farm holds 500 × 4.54609 = 2,273 L. Chemical spray rates on older agricultural equipment are given in fluid ounces or pints per gallon (imperial), requiring conversion to mL/L for modern calibration. Pump capacities on vintage farm irrigation equipment in AU gallons per hour need conversion to L/min for modern flow system design. New Zealand and UK agricultural archives also use imperial gallons — identical to the AU gallon — making the same conversion factor universally applicable across all former British Commonwealth agricultural data.
Some older Australian pool chemical dosing guides and treatment charts — particularly those from before 1980 or imported from the UK — express pool volumes in imperial gallons. A pool chemical dosing rate of "1 cup per 1,000 gallons" using the AU (imperial) gallon = per 4,546.09 L. Older Australian pool installation manuals may rate pump capacities in AU gallons per hour (GPH) rather than L/min. Converting a pool volume of 50,000 L to AU gallons: 50,000 ÷ 4.54609 = 10,998.5 AU gal ≈ 11,000 AU gal. Pool technicians and spa service professionals using legacy documentation need this conversion to apply correct chemical dosing to modern litre-based pool volume calculations.
Older Australian-built and UK-built vessels have fuel tank capacities stamped in imperial gallons. A boat with a 50 AU gal fuel tank holds 50 × 4.54609 = 227.3 L. Fuel consumption at sea for older vessels may be rated in AU gal/hour, requiring conversion to L/hour for modern engine monitoring systems. Marine engine manuals from British manufacturers use imperial gallons for coolant capacity, gearbox oil, and fuel consumption figures. Boaties refuelling at modern Australian marinas need to know that their vintage vessel's "40 gallon tank" means 40 AU gal = 181.84 L, not 40 US gallons (= 151.4 L) — a meaningful difference for trip planning.
Traditional British and Australian brewing recipes use imperial (AU) gallons. A classic homebrew recipe calling for 5 AU gallons = 5 × 4.54609 = 22.73 L — slightly larger than the common 5 US gallon (18.93 L) brew batch. Commercial Australian distilleries working from heritage recipes need to convert historical AU gallon batch sizes to modern litre-based production equipment. The Brewer's Association in Australia and traditional homebrew communities often reference both AU and US gallon sizes, with the 23 L (≈5 AU gal) fermenter being a standard Australian homebrew size. UK brewing references also use imperial gallons = AU gallon, making British recipe conversion straightforward with this calculator.
British-manufactured plumbing fittings, water heaters, pressure vessels, and industrial equipment imported into Australia may specify capacity in imperial gallons (= AU gallons). A UK water heater rated at 15 imperial gallons = 15 × 4.54609 = 68.19 L. Hydraulic equipment manuals from British manufacturers use imperial gallons for fluid capacities. Pressure washers, compressors, and industrial tanks imported from the UK and rated in imperial gallons need litre conversion for Australian compliance documentation and maintenance records. Building services engineers and facilities managers working with older or UK-origin plant and equipment in Australia routinely perform this conversion when updating maintenance schedules or specifying replacement fluid volumes.
1 AU gal = 4.54609 L (exact). 1 L = 0.219969 AU gal. 10 AU gal = 45.4609 L. 100 AU gal = 454.609 L. 1,000 AU gal = 4,546.09 L. AU vs US: 1 AU gal = 1.20095 US gal; 1 US gal = 0.832674 AU gal. AU gal subdivisions: 1 AU gal = 8 imperial pints = 160 imperial fluid ounces = 32 gills. Common tank sizes: 100 AU gal = 454.6 L; 200 AU gal = 909.2 L; 500 AU gal = 2,273 L; 1,000 AU gal = 4,546 L. Fuel economy: L/100km = 282.48 ÷ mpg(AU). Quick rule: L ÷ 4.55 ≈ AU gal (error <0.1%); AU gal × 4.55 ≈ L (error <0.1%). Always use the full factor 4.54609 for precision calculations.
The most critical error when working with gallons in Australia is confusing the Australian (imperial) gallon (4.54609 L) with the US gallon (3.78541 L) — they differ by about 20%. If you fill a US-made 10-gallon fish tank, it holds 10 × 3.785 = 37.85 L; but a pre-metric Australian 10-gallon tank holds 10 × 4.546 = 45.46 L. For dosing chemicals, filling fuel tanks, or purchasing replacement parts, using the wrong gallon type causes a 20% error that can have real practical consequences. Always check whether a gallon figure comes from Australian/UK (imperial) or American (US) sources before applying it. This calculator always displays both AU and US gallon results simultaneously so you can immediately see the difference and use the correct value.
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The International Bureau of Weights and Measures (BIPM) confirms the exact value of the imperial gallon as 4.54609 litres — established under the Weights and Measures Act 1985 (UK) and accepted internationally. The exact definition traces back to the Weights and Measures Act 1824 (UK), which defined the imperial gallon as the volume of 10 pounds avoirdupois of distilled water at 62°F under standard pressure. The modern exact metric value of 4.54609 L has been in force since the 1985 harmonisation of international units.
Visit BIPM →Australia's metrication was overseen by the Metric Conversion Board, established under the Metric Conversion Act 1970. The country progressively adopted SI units throughout the 1970s and 1980s, replacing imperial gallons with litres for all fuel, liquid, and commercial volume measurements. The Australian Government's National Measurement Institute (NMI) maintains official measurement standards and unit definitions for Australia, including the legal definition of the litre and the historical reference values for pre-metric imperial units including the gallon.
Visit NMI →Explore the full library of free unit converters on ConceteMetric.com — covering volume, temperature, pressure, length, weight, area, and energy. All tools are mobile-friendly, scientifically accurate, and completely free to use throughout 2026 with no sign-up required. New converters are regularly added across all unit categories.
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