Quarts to Liters Formula (qt to L) with Examples

Key Points

• The quarts to liters formula is $\text{litres} = \text{US liquid quarts} \times 0.946352946$, and the factor is exact because a US liquid quart is defined as exactly 57.75 cubic inches.

• Three different quarts exist: the US liquid quart at about 0.946 litres, the US dry quart at about 1.101 litres, and the Imperial quart at about 1.137 litres.

• One litre is about 1.057 US liquid quarts, which is why a litre bottle and a quart bottle look almost but not quite the same size.

• Four US liquid quarts make one US gallon, so the quart factor is simply the exact gallon figure of 3.785411784 litres divided by four.

• The rough claim that a quart equals a litre is about 5.4 per cent out, which matters for any recipe or dose scaled up more than a few times.

The Quarts to Liters Formula

To convert US liquid quarts to litres, multiply by 0.946352946:

$$\text{Volume in L} = \text{Volume in US liquid qt} \times 0.946352946$$

That is the conversion for the quart almost every everyday figure means. The Imperial quart and the US dry quart are separate units with their own factors, covered below.

Quarts to Litres Conversion Table

The 4-quart row is the useful anchor. Four US liquid quarts come to 3.7854 litres, which is exactly one US gallon, so the quart and gallon factors are the same definition at different scales.

Where the Quarts to Liters Formula Appears

Cooking is the most common setting, especially with American recipes read outside the United States. A recipe calling for 2 quarts of stock needs about 1.89 litres, and rounding that to 2 litres adds more than 100 millilitres.

Motor oil and automotive fluids are the other everyday case. Oil is sold by the quart in the United States and by the litre nearly everywhere else, so an engine specified to take 5 quarts needs about 4.73 litres rather than 5.

Dairy and juice packaging sits right on the confusion. A one-quart carton and a one-litre carton are close enough in size to be mistaken for each other, yet the litre holds about 5.4 per cent more.

What a Quart and a Litre Each Are

A quart is a quarter of a gallon, which is where its name comes from. Because there are two gallons in common use and the United States also keeps separate dry measures, there are three quarts in circulation rather than one.

A litre is a metric unit of volume equal to exactly one cubic decimetre and exactly 1000 millilitres, both of which NIST records as exact relationships. NIST also gives one litre as about 1.057 liquid quarts, which is the clearest statement of how close the two units are.

Why the Factor Is 0.946352946

The number follows from a definition rather than a measurement. A US liquid quart is exactly 57.75 cubic inches, and an inch is exactly 2.54 centimetres, so the volume is fixed.

Working it through, $57.75 \times 2.54^3 = 946.3529\ldots$ cubic centimetres, which is 0.9463529 litres. NIST Handbook 44's table prints 0.946 352 9.

The gallon route gives the same answer and is quicker to remember. A quart is a quarter of a US gallon, and the gallon is exactly 3.785411784 litres, so dividing by four gives 0.946352946 litres.

Step 1. Establish which quart the figure means, since US liquid is the usual answer but not the only one.

Step 2. Multiply by 0.946352946 for US liquid quarts, 1.1012 for US dry quarts, or 1.1365 for Imperial quarts.

Step 3. Round at the end, to the precision the task needs.

For mental work, treating a quart as 0.95 litres is accurate to within a twentieth of a per cent, which is far better than treating it as a litre.

Examples of the Quarts to Liters Formula

Example 1

Convert 1 US liquid quart to litres.

$$\text{L} = 1 \times 0.946352946 = 0.946352946$$

Final answer: about $0.9464 \text{ L}$

Example 2

Convert 3 quarts to litres by treating a quart as one litre.

A quart and a litre are close enough that the substitution looks harmless, and it saves a calculation. Try it:

$$3 \text{ qt} \approx 3 \text{ L}$$

The true answer is 2.839 litres, so the shortcut has invented 161 millilitres of liquid. In a sauce that is a visible difference in consistency, and in a measured dose it is an error of more than 5 per cent.

The gap is fixed in proportion, which is what makes it misleading. It stays at 5.4 per cent whether the quantity is one quart or fifty, so scaling a recipe up scales the error with it.

$$\text{L} = 3 \times 0.946352946 = 2.839058838$$

Final answer: about $2.8391 \text{ L}$

Example 3

Convert 5 quarts of motor oil to litres.

$$\text{L} = 5 \times 0.946352946 = 4.73176473$$

Final answer: about $4.73 \text{ L}$

An engine needing 5 quarts takes less than 5 litres, so buying a 5-litre container leaves a little over rather than falling short.

Example 4

Convert 4 quarts to litres and name the result.

$$\text{L} = 4 \times 0.946352946 = 3.785411784$$

Final answer: exactly $3.785411784 \text{ L}$, which is one US gallon.

Example 5

Convert 2 Imperial quarts to litres.

$$\text{L} = 2 \times 1.1365 = 2.273$$

Final answer: about $2.273 \text{ L}$

The same number of Imperial quarts gives roughly 20 per cent more volume than US liquid quarts, because the Imperial gallon they come from is about 20 per cent larger.

Example 6

A recipe for 12 servings uses 3 quarts of stock. Scale it to 20 servings and give the answer in litres.

Scale first, then convert once:

$$3 \times \frac{20}{12} = 5 \text{ qt}$$ $$\text{L} = 5 \times 0.946352946 = 4.7318$$

Final answer: about $4.73 \text{ L}$

Scaling in the original unit and converting at the end keeps the arithmetic simpler and avoids rounding twice.

Quarts to Liters, Common Confusions Cleared Up

Mistake 1: Treating a quart as a litre

Where it slips in: The two units are close, and the substitution is fast, so it gets used as a rule of thumb and then forgotten.

Don't do this: $3 \text{ qt} = 3 \text{ L}$

The correct way: $3 \times 0.946352946 = 2.839 \text{ L}$. The error is 5.4 per cent and it scales with the quantity rather than washing out.

Students who carry 0.95 instead of 1 as their mental factor get within a twentieth of a per cent for no extra effort. Picking a slightly harder round number is usually the better trade in any estimation work.

Mistake 2: Using the wrong quart

Where it slips in: Three quarts exist, all abbreviated qt, and sources rarely say which they mean.

Don't do this: Apply the US liquid factor to an Imperial quart or a dry quart figure.

The correct way: Default to the US liquid quart for liquids, and check the source if the measurement is of grain, berries or other dry goods. The Imperial quart is about 20 per cent larger and the dry quart about 16 per cent larger.

Mistake 3: Dividing instead of multiplying

Where it slips in: The factor is less than 1, which makes it look like a divisor.

Don't do this: $3 \div 0.946352946 = 3.17 \text{ L}$

The correct way: $3 \times 0.946352946 = 2.839 \text{ L}$. A quart is smaller than a litre, so the litre figure must be the smaller number, and an answer larger than the quart count is wrong on sight.

Quarts to Liters in Five Bullets

• The quarts to liters formula multiplies US liquid quarts by 0.946352946, a factor exact by definition.

• The definition is 57.75 cubic inches, which is also one quarter of the exact 231-cubic-inch US gallon.

• Three quarts exist, and the US liquid quart is the only one smaller than a litre.

• Treating a quart as a litre is 5.4 per cent out, and the error scales rather than averaging away.

• To work on volume and unit conversion with a teacher, explore a 7th grade math tutor or primary math tuition.

Sharpen Your Quarts to Liters Conversion

Convert 6 quarts, 1.5 quarts and 10 quarts to litres. Then check the 10-quart answer against 2.5 US gallons, which should give the same volume.

Want a live Bhanzu trainer to walk through more volume conversion problems? Book a free demo class.

Read More

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• Volume Formula

• What Is a Unit

• What Is Proportion

• Ratio Formula