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Cups to Milliliters Converter

Convert US cups to milliliters — the number to pour when the jug is marked in metric.

Updated

milliliters

236.59mL

1 cup = 236.59 mL

In short

How many mL is a cup?

One US cup is 236.59 millilitres, from the exact figure 236.5882365. No metric measuring jug has a mark for it, which is the real difficulty. The metric cup used in Australia and New Zealand is a round 250 millilitres, and the cup the FDA prints on nutrition labels is 240.

A US quart is four cups, which comes to 946.35 mL — about 5.67 percent short of a litre.

US cups to milliliters — quick reference

US cups (cup)milliliters (mL)
0.3 cup59.15 mL
0.3 cup78.07 mL
0.5 cup118.29 mL
0.8 cup177.44 mL
1 cup236.59 mL
1.5 cup354.88 mL
2 cup473.18 mL
4 cup946.35 mL
Computed from the exact factor — rounded only for display.

The formula, worked line by line

The conversion multiplies by a constant that was defined rather than measured. A US cup is eight US fluid ounces, the fluid ounce is one hundred and twenty-eighth of the US liquid gallon, and the gallon is exactly 231 cubic inches. Fixing the inch at 2.54 centimetres in 1959 made every figure downstream exact.

The US gallon is exactly 231 cubic inches, and the inch is exactly 2.54 centimetres.
International Yard and Pound Agreement, 1959

The arithmetic contributes no error whatsoever. Everything that goes wrong happens afterwards, at the jug mark and in the decision about how to round, which is why the rest of this page is about rounding policy rather than about decimal places.

mL = cups x 236.5882365
236.5882365 = 29.5735295625 x 8   (eight fluid ounces)
1 cup -> 1 x 236.5882365 = 236.59 mL
4 cups -> 4 x 236.5882365 = 946.35 mL, one US quart
US cup = 8 fl oz = 16 tbsp = 48 tsp
US cups against millilitersA twin scale: US cups along the top against milliliters along the bottom, with 1 cup marked.cupmL001236.592473.183709.764946.35cupmL
One US cup is 236.59 mL. Read the cup scale against the millilitre scale.
The worked default, one cup
Cups entered
1
Exact factor
236.5882365 mL per cup
Multiplication
1 x 236.5882365 = 236.5882365
Millilitres
236.59 mL

Rounding that to a convenient 240 runs 1.44 percent high and matches the FDA labelling cup. Rounding to 250 runs 5.67 percent high and matches the Australasian metric cup. Rounding down to 235 runs 0.67 percent low and matches nothing, which is often the best choice because it is closest.

Below a quarter cup, use spoons

A cup is exactly 16 tablespoons and 48 teaspoons, so small quantities convert with no rounding at all. A quarter cup is four tablespoons and an eighth is two. A jug graduated every 25 millilitres cannot show 59.15, but a tablespoon measure can deliver it four times over exactly.

Small cup fractions as exact spoon counts
One sixteenth cup
1 tablespoon, 14.79 mL
One eighth cup
2 tablespoons, 29.57 mL
One quarter cup
4 tablespoons, 59.15 mL
One third cup
5 tablespoons plus 1 teaspoon
One half cup
8 tablespoons, 118.29 mL

The third-cup only works out cleanly in teaspoons, because 48 divides by three where 8 and 16 do not.

This converts volume, never weight

A cup is a measure of space. Filling one with flour gives about 120 grams and filling it with honey gives about 340, from the same 236.59 millilitres. Converting cups to millilitres tells you nothing about mass, and any tool offering a single cups-to-grams factor is applying one ingredient density to all of them.

How to use the cups to milliliters converter

A US cup is 236.5882365 millilitres, which is eight fluid ounces. The fluid ounce is a US gallon of exactly 231 cubic inches split into 128 parts, so the long decimal is the signature of an exact definition rather than a measurement. Nothing in the chain is approximate.

The problem this creates is practical rather than mathematical. A metric measuring jug is graduated every 25 or 50 millilitres, and 236.59 falls between marks. So does half a cup at 118.29, and a quarter at 59.15. Every American liquid quantity lands somewhere a metric jug cannot show precisely.

236.59 mL

One US cup

no jug is marked for it

946.35 mL

Four cups, one US quart

5.67 percent under a litre

78.07 mL

A third of a cup

entered as 0.33

The temptation is to round each quantity as you go, and that is where recipes break. Rounding a cup up to 250 and a half cup down to 100 pushes the two ingredients apart by more than either error alone. Ratios are what a batter, a brine and a dough actually depend on.

Where a quantity is small enough, skip the jug entirely. Below about 60 millilitres a set of spoons is more accurate than any graduation, and the US measures convert exactly: a quarter cup is four tablespoons, an eighth is two, and a sixteenth is one. No rounding is involved at all.

US cup quantities in millilitres
0.25 cup, four tablespoons
59.15 mL
0.33 cup
78.07 mL
0.5 cup
118.29 mL
1 cup
236.59 mL
2 cups, one US pint
473.18 mL
4 cups, one US quart
946.35 mL

Not one of these lands on a jug mark. That is the reason an American recipe feels awkward in a metric kitchen, and it has nothing to do with the arithmetic being hard.

When the recipe is measuring a solid

A cup of flour, sugar, butter and honey weigh 120, 200, 227 and 340 grams. Millilitres cannot tell you that, because volume carries no information about mass without a density.

Open the cups to grams converter

US cups converted to millilitres, with the nearest jug mark alongside and the error that rounding to it introduces. The third column is what you would actually pour.

US cupsMillilitresNearest 25 mL mark
0.25 cup59.15 mL50 mL, 15 percent low
0.33 cup78.07 mL75 mL, 3.9 percent low
0.5 cup118.29 mL125 mL, 5.7 percent high
0.67 cup158.51 mL150 mL, 5.4 percent low
0.75 cup177.44 mL175 mL, 1.4 percent low
1 cup236.59 mL225 mL, 4.9 percent low
1.5 cups354.88 mL350 mL, 1.4 percent low
2 cups473.18 mL475 mL, 0.4 percent high
3 cups709.76 mL700 mL, 1.4 percent low
4 cups946.35 mL950 mL, 0.4 percent high
6 cups1,419.53 mL1,425 mL, 0.4 percent high
8 cups1,892.71 mL1,900 mL, 0.4 percent high
16 cups3,785.41 mL3,785 mL, one US gallon
Definitions, not measurements: 1 US cup = 8 US fluid ounces = 236.5882365 mL, from the US liquid gallon of 3.785411784 L. Millilitres are rounded to two decimals for display only.

Rounding once versus rounding often

Converting a recipe is not a series of independent conversions. Each ingredient is in a relationship with the others, and a rounding applied to one but not the rest breaks that relationship. This is why a translated recipe can be wrong even when every individual number in it is defensible.

The failure is easiest to see in a dough. Flour and water in a fixed proportion make a hydration, and hydration decides whether the dough is workable. Round the water up to a jug mark and leave the flour at its converted weight and the hydration moves, sometimes by enough to change how the dough handles.

A two-ingredient batter, rounded two ways
Recipe as written
2 cups liquid, 1 cup liquid flavouring
Exact conversion
473.18 mL and 236.59 mL
Rounded to the nearest 25 mL
475 mL and 225 mL
Ratio, before and after
2.000 against 2.111
Drift introduced
5.6 percent, from rounding alone

Both rounded figures are within 5 percent of correct on their own, and the ratio between them has moved by 5.6 percent because they rounded in opposite directions. Rounding both to the nearest 25 in the same direction would have kept the ratio at 2.0 exactly.

The general rule follows from that: consistency beats precision. A recipe scaled with a slightly wrong cup but the same wrong cup throughout will work. A recipe scaled with the right cup and inconsistent rounding may not, which is the opposite of what most people expect.

Which cup the recipe means

This page converts the US customary cup of 236.59 millilitres, which is what an American recipe means. Two other cups are in circulation. The metric cup used in Australia and New Zealand is a round 250 millilitres, 5.67 percent larger. The FDA defines a 240 millilitre cup for nutrition labelling, 1.44 percent larger.

The labelling cup appears in the Code of Federal Regulations alongside a 15 millilitre tablespoon, a 5 millilitre teaspoon and a 30 millilitre fluid ounce. Those are deliberate roundings chosen for packaging rather than conversions of the customary units, which is why a package and a recipe can disagree slightly without either being wrong.

Three cups, and the gap between them
US customary cup
236.59 mL
FDA nutrition-label cup
240 mL, 1.44 percent larger
Metric cup, Australia and New Zealand
250 mL, 5.67 percent larger
Across a four-cup recipe
54 mL of difference

Fifty-four millilitres across a four-cup recipe is about three and a half tablespoons. In a stew that is invisible; in a set custard it is not.

The imperial system never had a cup at all, which is a useful tell. British and Irish recipes traditionally weigh dry ingredients, so a recipe written in cups is American or Australasian. If it also uses ounces for solids, it is almost certainly American and the 236.59 millilitre cup applies.

Every US cups value, worked out

35 common US cups figures each get their own page, with the answer at full precision, the arithmetic, what rounding costs, and the nearest real-world reference point on the scale.

Questions people ask

Sources

Where the constants and formulas on this page come from. Each line names the figure it backs.

  1. The US cup is eight US fluid ounces of exactly 29.5735295625 millilitres each, giving 236.5882365 mL.

    NIST Guide to the SI, Appendix B.8 — Factors for units listed alphabeticallyNIST

  2. For nutrition labelling the FDA defines a cup as 240 mL, a tablespoon as 15 mL and a teaspoon as 5 mL.

    21 CFR 101.9(b)(5)(viii) — Nutrition labeling of foodUS Food and Drug Administration, via the eCFR