A 15 oz jar of mayonnaise holds about 1.9 cups. The bag weighs 425 g, and one cup of mayonnaise weighs 220 g, so 425 divided by 220 is 1.9. The figure is approximate, because cup weights vary with how the cup is filled and how settled the contents are, so if the recipe matters, weigh the mayonnaise on a kitchen scale instead of counting cups from the package. For everyday cooking, 1.9 cups is the number to plan with.

Emulsified oil, egg and vinegar spread. Sandwiches, dressings, dips and coleslaw. Knowing how many cups are in the package answers the question every cook asks in the shop: is this bag enough for the recipe, or do I need two? A 15 oz jar that holds 1.9 cups covers a recipe needing 1 cup 1.93 times over, but falls 0.1 cups short of a recipe needing 2 cups — for that recipe, buy two. Buy the size that covers your regular recipes with a little to spare, and you will stop running out halfway through a bake.

Package sizes to cups conversion table

Package size Weight Cups (approx.)
4 oz 113.4 g 0.5 cups
8 oz 226.8 g 1 cups
12 oz 340.19 g 1.5 cups
15 oz 425.24 g 1.9 cups
16 oz 453.59 g 2.1 cups
26 oz 737.09 g 3.4 cups
32 oz 907.18 g 4.1 cups
64 oz 1814.37 g 8.2 cups
80 oz 2267.96 g 10.3 cups
1 lb 453.59 g 2.1 cups
2 lb 907.18 g 4.1 cups
4 lb 1814.36 g 8.2 cups

The table covers the common package sizes for mayonnaise, from a small 4 oz pack up to a 4 lb bag. The 15 oz jar in the headline is the 425 g size, which holds 1.9 cups. The gram column is the reliable one: package weights are printed on the label and do not change, while cup counts depend on how the cup is filled. If you are scaling a recipe, work in grams — a cup of mayonnaise is 220 g — and the package arithmetic becomes exact.

Cups, grams and tablespoons

One cup of mayonnaise weighs 220 g, measured spooned and levelled. The table below breaks that cup down into the smaller measures recipes actually use, so you can measure a spoonful from the package without opening a second container.

Measure Grams (approx.)
1 teaspoon 4.6 g
1 tablespoon 13.8 g
2 tablespoons 27.5 g
1/4 cup 55 g
1/2 cup 110 g
1 cup 220 g

A tablespoon of mayonnaise is 13.8 g and a teaspoon is 4.6 g. For small amounts, spoon measures are more accurate than cups: a recipe that needs 2 tablespoons takes 27.5 g, and measuring that in a cup would mean eyeballing an eighth of a cup, which nobody can do reliably. Use the spoon figures for anything under a quarter cup, and the cup figures for anything above it.

Worked examples

A dip for a party

A dip for a party of eight uses about 1 cup of mayonnaise, which is 220 g. The 15 oz jar holds 1.9 cups, so one container makes 1.9 dips at one cup each. Mix the dip the night before and chill it overnight — the flavours meld as it sits, and a dip made an hour before the party always tastes flatter than one made the day before. Taste it cold before serving, because chilling dulls flavour: a dip that tasted perfect at room temperature usually needs a pinch more salt and a squeeze of lemon once it is cold. Serve it in a bowl set over ice if it will sit out for hours.

A salad dressing that uses the whole bottle

A vinaigrette that serves four uses about 1/4 cup of mayonnaise whisked with 3/4 cup of oil, a teaspoon of mustard and a pinch of salt. The 15 oz jar holds 1.9 cups, so one container makes about 7.73 batches of dressing. Whisk the mayonnaise with the mustard first, then add the oil in a slow stream while whisking — the mustard is what holds the emulsion together, and without it the dressing separates in minutes. The dressing keeps for a week in a jar in the fridge; shake it well before using, because the oil and mayonnaise will separate as it sits. Taste before serving: a dressing that is too sharp needs a pinch of sugar, not more oil.

A marinade for a weekend grill

A marinade for a kilogram of chicken or a flank steak uses about 1/2 cup of mayonnaise, which is 110 g. The 15 oz jar holds 1.9 cups, so one container makes about 3.86 marinades. Mix the marinade in a bowl, pour it over the meat in a sealed bag, and turn the bag once halfway through so the marinade reaches every side. Marinate for at least an hour and no more than overnight for acidic marinades — acid starts to break down the surface of the meat if it sits too long, and the texture turns mushy instead of tender. Reserve a little marinade before the meat goes in if you want a sauce, because marinade that has touched raw meat must be boiled before serving.

How the figure is worked out

The calculation depends on whether the package is sold by weight or by volume. This 15 oz jar is sold by weight: it contains 425 g of mayonnaise, and one cup weighs 220 g, so 425 divided by 220 is 1.9 cups. There is no other step. The package size is printed on the label, the cup weight comes from USDA, and the division gives the answer.

The cup weight itself is where the uncertainty lives. One cup of mayonnaise weighs 220 g, measured spooned and levelled from a US cup of 236.6 ml. The figure comes from USDA and carries medium confidence in our table. A cup is a volume, not a weight, so anything that changes how much of the ingredient fits in that volume changes the weight: how firmly it is packed, how fine the grind is, how much moisture it has absorbed, and whether it was spooned or scooped. That is why this page labels every result approximate and why a scale is the only way to be certain.

Practical guidance

Emulsified oil, egg and vinegar spread. Sandwiches, dressings, dips and coleslaw. Refrigerate after opening; use within 2 months.

The most common mistake with mayonnaise is measuring it the wrong way for its form. Measure mayonnaise in the right tool for its form — a liquid in a jug read at eye level, a dry ingredient spooned and levelled in a dry cup, a thick paste pressed into the cup to remove air pockets. A cup of mayonnaise weighs 220 g, and that figure assumes the standard method (spooned and levelled), so a different method gives a different weight. When a recipe depends on the amount — a sauce that must thicken, a dough that must hold together — weigh it instead of measuring it, and write the gram figure on the recipe card for next time.

If you do not have a scale, the cup figures on this page will get you close enough for everyday cooking, but not for precision baking. A basic digital kitchen scale costs little, weighs in grams, and removes the single biggest source of variation in baking. Until you have one, spoon and level dry ingredients, use a liquid jug for liquids, and never scoop from the bag.

Frequently asked questions

How many cups are in a 15 oz jar of mayonnaise?

About 1.9 cups. The headline figure comes from the package size divided by the cup weight: one cup of mayonnaise weighs 220 g, so the contents of the 15 oz jar work out to 1.9 cups. The figure is approximate, because cup weights vary with how the cup is filled and how settled the contents are.

How many grams are in a 15 oz jar of mayonnaise?

About 425 g — 1.9 cups at 220 g per cup. The package label gives the net weight, so the gram figure is exact where the cup figure is approximate.

How many tablespoons are in a 15 oz jar of mayonnaise?

About 30.91 tablespoons. There are 16 tablespoons in a cup, and the 15 oz jar holds 1.9 cups, so 1.9 times 16 is 30.91. That is 92.73 teaspoons.

Is the cup count exact, or should I weigh it?

It is approximate. The cup count is worked out from the cup weight of 220 g, and that weight assumes the standard method (spooned and levelled). If the recipe matters — a cake, a frosting, a sauce that must set — weigh the ingredient on a kitchen scale instead of counting cups from the package. For everyday cooking, the 1.9-cup figure is close enough.

How should I store the rest of the 15 oz jar once it is open?

Refrigerate after opening; use within 2 months. Once opened, keep the container sealed between uses so the contents stay fresh and the weight per cup stays consistent — an open bag absorbs moisture from the air, which changes both the flavour and the cup weight.

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