Convert gal to L US gallons ↔ litres Free Online Secure
Type a value in US gallons and read it in litres at once. The factor is exact by definition, the arithmetic happens in your browser, and nothing is sent anywhere.
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Common values — Convert gal to L (US gallons ↔ litres)
| gal | L |
|---|---|
| 1 | 3.785411784 |
| 2 | 7.570823568 |
| 3 | 11.356235352 |
| 5 | 18.92705892 |
| 10 | 37.85411784 |
| 20 | 75.70823568 |
| 50 | 189.2705892 |
| 100 | 378.5411784 |
Where these units come from
The litre has an awkward history. From 1901 it was defined as the volume of one kilogram of pure water at its densest, which sounds elegant but came out at 1.000028 cubic decimetres — close enough to be confusing and far enough to spoil careful work. In 1964 the definition was abandoned and the litre became exactly one cubic decimetre, which it has been ever since. The gallon has a messier story still: the US gallon descends from the English wine gallon of 231 cubic inches, while Britain redefined its own in 1824 as the volume of ten pounds of water. Nobody reconciled the two, so a US gallon is 3.785411784 litres and an imperial gallon 4.54609 — about a fifth larger. The gallon, pint, cup, fluid ounce and spoons on this page are the US ones.
Where you meet them
Millilitres and litres run through daily life almost invisibly: bottles, fuel, paint, dosage, the capacity of a kettle. Cubic metres belong to water bills, concrete, shipping and the air a ventilation system has to move. Cubic centimetres name engine displacement, cubic feet appear in freight and in appliance capacities, and cups and spoons live almost entirely in recipes — which is exactly where the difference between a US cup and a metric one quietly ruins a cake.
Questions people ask
Why is a US gallon smaller than a British one?
Because they were defined from different things and never reconciled. The US kept the old English wine gallon of 231 cubic inches, which gives 3.785411784 litres exactly. Britain started over in 1824 and defined the imperial gallon from the volume of ten pounds of water, now fixed at 4.54609 litres. The imperial gallon is therefore about 20% larger, and the same difference runs through the pint and the quart.
Is a litre of water really a kilogram?
Very nearly. The kilogram was first defined as the mass of one litre of water, and the two are still close: water at about 4 °C is 0.99997 kilograms per litre. It is not exact today because the kilogram is now defined from a physical constant. Warm water is slightly lighter, so the rule is a good approximation and not a law.
Is the answer exact?
Where both units are defined in terms of one another by whole numbers, yes — the page says so above the figure, and the only rounding is in how many digits are shown. Where the ratio has no finite decimal, the page shows twelve significant digits and says the relation is approximate rather than pretending otherwise.
Does anything I type leave my device?
No. The arithmetic runs in your browser; nothing is uploaded and there is no server to upload it to. Load the page once and it keeps working with the network switched off.
Milk jugs, paint cans and shower heads: the household gallon in litres
In an American home almost everything liquid comes by the gallon: the jug of milk in the fridge, the can of paint in the garage, the flow of water from the shower. If you cook, decorate or save water with a guide written in gallons, you need to convert gal to L. Multiply by 3.785: a gallon of milk is 3.785 litres, a 5 gallon water jug 18.9 litres and a shower head rated at 2.5 gallons per minute pours 9.5 litres every minute. This page multiplies as you type, and the text below tours the household with the factor in hand.
Ahead you will find the rule with examples, a note on each unit, a comparison, a walk through the home and garden and the slips to avoid. All arithmetic happens in your browser; nothing you enter is sent anywhere.
How to convert gal to L: multiply by 3.785411784
The rule
A US gallon is defined as 231 cubic inches, which is exactly 3.785411784 litres. To convert gal to L, multiply the gallons by 3.785, or by 3.8 for a quick figure. So 2 gal is 7.57 L, 5 gal is 18.9 L and 10 gal is 37.9 L. In the other direction, divide litres by 3.785.
Worked examples
A half-gallon carton is 1.89 litres. A 5 gallon bucket is 18.9 litres. A 10 gallon aquarium is 37.9 litres. A 55 gallon rain barrel is 208 litres. If you want a fast answer, multiply by 4 and take off 5 percent.
Why not 4.546
The British imperial gallon is 4.546 litres, about 20 percent larger than the American one. Older British and some Commonwealth recipes and manuals use it. If you are reading an American label, use the US gallon, 3.785 litres, and if the source is British, check which gallon is meant.
A quick sanity check
The litre is the smaller unit, so the number grows by nearly four times. If your “convert gal to L” calculation result grew only twofold or threefold, something is wrong with the factor.
The US gallon
231 cubic inches
The US gallon is made of 4 quarts, 8 pints, 16 cups or 128 fluid ounces. It is the household unit of milk, paint, water, fuel and cleaning products in the United States.
Where it appears
Grocery labels, hardware stores, water bills and appliance manuals.
The litre
A cube of ten centimetres
The litre is the unit of liquid volume in most of the world. Drinks, paints and fuel are sold in it, and it is the base for millilitres and cubic metres.
Where it appears
Bottles, cans, cartons and utility bills.
Gallon and litre compared
A US gallon holds nearly 3.8 litres. A carton of milk in the United States is bigger than a four-pint bottle in Britain, and about the same as four litre cartons less a few spoonfuls. Anyone who moves across the Atlantic soon learns to think of a gallon as four litres.
The factor is not round, so mental estimates are approximate: multiply by 4 and subtract 5 percent. For exact work, use 3.785411784.
Where the conversion appears
In the kitchen
A gallon of milk is 3.785 litres, a half-gallon 1.89 litres, a quart 0.946 litres. A gallon jug of water is also 3.785 litres. A family that drinks a gallon of milk a week uses about 0.54 litres a day. A recipe for a large pot of soup that calls for 2 gallons wants 7.6 litres of stock. The “convert gal to L” calculation step turns such recipes into familiar measures.
In the bathroom
A modern toilet uses 1.28 to 1.6 gallons per flush, 4.8 to 6 litres. A shower head rated at 2.5 gallons per minute gives 9.5 litres a minute, and a water-saving one at 1.5 gpm 5.7 litres. A ten-minute shower uses 25 gallons, 95 litres, with the older head. Water-saving labels use gallons, and the conversion shows what they mean.
In the garage and garden
A gallon of paint covers 350 to 400 square feet, 32 to 37 square metres, which is 8.6 to 9.8 square metres a litre. A gallon of windscreen washer fluid is 3.785 litres. A lawn needs about an inch of water a week; on 1,000 square feet that is 623 gallons, 2,358 litres.
The five gallon bucket
The five gallon bucket is a universal container in American homes and workshops. It holds 18.9 litres, nearly 19 kg of water or about 25 kg of wet sand. A bucket of paint, a drum of cleaner and a bucket of mortar all use it. Because it is so common, a number of recipes and chemical dilutions are written for it, and a European user has to convert gal to L to use them with a 10 litre or 15 litre bucket.
Ice cream and dairy
Ice cream sold in 1.5 quart tubs is 1.4 litres, a half-gallon 1.89 litres, a gallon 3.785. A pint, one eighth of a gallon, is 473 ml. Pricing per gallon makes the cost of a big tub easy to compare, and anyone comparing with European litre tubs divides the price by 3.785 to get a price per litre.
Fuel for a home generator
A portable generator with a 5 gallon tank holds 18.9 litres. At half load it may burn 0.75 gallons per hour, 2.8 litres, and run for about seven hours. A whole-house standby unit uses propane in gallons or cubic feet. Storm preparation guides in the United States give quantities in gallons, so the conversion helps a reader outside the country plan fuel.
In a spreadsheet
Put gallons in column A and use =A2*3.785411784 in column B. For the reverse, =B2/3.785411784. A column of prices per gallon divided by 3.785411784 gives prices per litre. Format volumes with one decimal and prices with two, and keep the source column so you can check each number against the original label.
Rounding
The factor is exact, so rounding is your choice. Labels use whole or half gallons, so 2 gallons gives 7.6 litres, not 7.570823568. Prices are rounded to the cent. Round at the end of the calculation and keep the full figure while you work, especially when converting several quantities that will be added.
A mental shortcut
Multiply gallons by 4 and take 5 percent off. For 10 gallons, 40 minus 2 is 38 litres, against 37.85. For 25 gallons, 100 minus 5 is 95, against 94.6. The error is under half a percent, good enough for shopping. For a price per litre, divide the gallon price by 4 and add 5 percent.
Reference values
1 gal is 3.79 L, 2 gal is 7.57 L, 5 gal is 18.9 L, 10 gal is 37.9 L, 20 gal is 75.7 L, 50 gal is 189 L, 55 gal is 208 L and 100 gal is 379 L. If you convert gal to L and land far from this ladder, repeat the multiplication.
Checking by reversing
To make sure your “convert gal to L” calculation result is right, divide it by 3.785. If 5 gal gave 18.9 L, then 18.9 divided by 3.785 returns 5. A second check is the size of the answer: it should be nearly four times larger. If it is only about twice, or five times, a wrong factor was used.
Cars, oil and coolant
A car cooling system holds 1.5 to 3 gallons, 5.7 to 11.4 litres. An oil sump takes 4 to 6 quarts, 1 to 1.5 gallons. A windscreen washer reservoir holds a gallon or two. Auto parts stores sell antifreeze by the gallon, and the usual 50 to 50 mix means a gallon of concentrate with a gallon of water makes 2 gallons, 7.6 litres, of coolant.
Hand sprayers and garden tanks
A pump sprayer of 1 gallon holds 3.785 litres, a backpack sprayer of 4 gallons 15.1 litres. Weed killer labels specify ounces per gallon: 2.5 ounces per gallon is 74 ml in 3.785 litres, about 19.5 ml per litre. For a 15 litre tank, 293 ml are needed. Always follow the label, and use the conversion only to apply the rate, not to change it.
Camping water and hydration
Backpackers plan about a gallon of water per person per day for drinking and cooking in dry country, 3.8 litres, and a collapsible container of 2.5 gallons, 9.5 litres, serves four for a day. Weight matters: a gallon of water weighs 8.3 pounds, 3.8 kg. Planning a trip means working out the total volume in gallons or litres, and which the maps and guides use depends on the country.
Water jugs and coolers
An office water cooler uses 5 gallon bottles, 18.9 litres, which weigh about 19 kg when full. A home jug is 1 gallon, 3.785 litres. The common health advice to drink about a gallon of water a day means 3.8 litres, though needs vary. Water dispensers and refill stations in the United States are rated in gallons, and the conversion tells you how many glasses of 250 ml each jug holds.
Humidifiers and dehumidifiers
A console humidifier may evaporate 3 gallons a day, 11.4 litres, and a dehumidifier of 50 pints a day removes 6.25 gallons, 23.7 litres. Capacity ratings in the United States use pints or gallons per day, and in Europe litres per day. When you convert gal to L, a buyer can see that a 50 pint machine is about a 24 litre one.
Hot water for a household
An American family may use 60 to 80 gallons of hot water a day, 227 to 303 litres. A 50 gallon tank, 189 litres, supplies a shower of 10 gallons, 38 litres, for about five people in a morning. Water heater sizes in the United States are in gallons, and a European installer comparing a cylinder in litres needs a clean conversion to select the right size.
Recreational vehicles
An RV may carry 40 gallons of fresh water, 151 litres, 30 gallons of grey water, 114 litres, and a 20 gallon propane tank. A couple using 10 gallons a day, 38 litres, empties the fresh tank in four days. Motorhome brochures give gallons, and European campsites speak of litres, so converting the tank sizes helps with trip planning on either side.
Pets and livestock troughs
A large dog drinks about a gallon of water a day, 3.8 litres, while a horse drinks 5 to 10 gallons, 19 to 38 litres, and a dairy cow 25 gallons or more, 95 litres. A stock trough of 100 gallons holds 379 litres. Farm supply catalogues quote gallons, and a keeper outside the United States who wants to size a tank per animal has to convert gal to L for each figure.
Slow cookers and stock pots
A slow cooker is sold by its capacity in quarts, a quart being a quarter gallon. A 6 quart cooker holds 1.5 gallons, 5.7 litres. A large stock pot of 12 quarts, 3 gallons, is 11.4 litres. Recipes for gatherings are written in gallons for drinks, such as 2 gallons of punch, 7.6 litres, to serve 60 cups of 4 ounces. A conversion helps scale the recipe to local equipment.
Washing machines and dishwashers
An older top-loading washing machine can use 40 gallons per load, 151 litres. A modern high-efficiency model uses 13 to 20 gallons, 49 to 76 litres. A dishwasher uses 3 to 6 gallons per cycle, 11 to 23 litres. Energy and water labels in the United States give gallons, so a family comparing with a European model, which quotes litres per cycle, needs the factor 3.785.
Lawn watering
An inch of water over a square foot is 0.623 gallons, 2.36 litres. A lawn of 2,000 square feet needs 1,246 gallons, 4,716 litres, for an inch. That is 4.7 cubic metres. Sprinklers deliver 0.5 to 2 gallons per minute per head, 1.9 to 7.6 litres, so running time can be worked out once the delivery is in the same unit as the need.
Rain barrels
A rain barrel of 55 gallons holds 208 litres. A roof of 1,000 square feet catches 623 gallons, 2,358 litres, from a one inch rainfall, enough to fill eleven such barrels. Gardeners collect the water and apply it with a can, so a barrel's volume in litres helps compare it with a typical 10 litre watering can: 20 cans per barrel.
Hot tubs and small pools
A hot tub of 400 gallons holds 1,514 litres. A paddling pool of 100 gallons holds 379 litres. A backyard pool of 15,000 gallons holds 56.8 cubic metres. Chemical doses are given per 10,000 gallons, so a European owner works out the volume in litres, then the dose in grams or millilitres per 1,000 litres. The “convert gal to L” calculation step comes first.
Cleaning concentrates and dilution
Concentrates are diluted by the ounce per gallon: 4 ounces per gallon is 118 ml in 3.785 litres, about 31 ml per litre. A 5 gallon bucket needs 20 ounces, 591 ml. Floor cleaners and sanitisers have a stated dilution on the label, and for a metric user it helps to convert the gallon to litres and the ounces to millilitres before measuring.
More values for convert gal to L
A longer list of conversions
If the value you need is not in the first list, these further conversions may be close enough to read off directly:
- 0.1 gal = 0.3785411784 L
- 0.5 gal = 1.892705892 L
- 3 gal = 11.356235352 L
- 4 gal = 15.141647136 L
- 7 gal = 26.497882488 L
- 15 gal = 56.78117676 L
- 20 gal = 75.70823568 L
- 75 gal = 283.9058838 L
- 200 gal = 757.0823568 L
- 500 gal = 1,892.705892 L
- 2,000 gal = 7,570.823568 L
- 10,000 gal = 37,854.11784 L
Mistakes when you convert gal to L
Mixing US and imperial gallons
The imperial gallon is 4.546 litres. Check which one your source uses.
Comparing prices without converting
A price per gallon is not comparable with a price per litre. Divide by 3.785 first.
Dividing instead of multiplying
The litre is the smaller unit, so the number grows. If 5 gal became 1.32, you divided.
Quick answers
How many litres are in a US gallon?
3.785.
How do I convert gal to L?
Multiply by 3.785.
How many gallons are in a litre?
0.2642.
What is 5 gal in litres?
18.9 L.
Does the number I type leave my device?
No, it stays in your browser.
More pages and a closing note
For other volume conversions, see Convert gal to qt, Convert cm³ to L, Convert m³ to L, Convert L to m³, Convert km to mi, Convert mi to km, Convert °C to °F, Convert °F to °C, Convert m to nm. The opposite direction is Convert L to gal.
In short, you convert gal to L by multiplying by 3.785 and writing the unit beside the answer. Your figure is calculated on your own device, with no account and no upload.