1 teaspoon of mayonnaise weighs 4.58 g. A teaspoon is one forty-eighth of a cup, and a cup of mayonnaise is 220 g spooned and levelled, so the maths is 220 ÷ 48 = 4.58 g. The same cup divided by 16 gives the tablespoon weight of 13.8 g, and there are 3 teaspoons in every tablespoon. If you cook from recipes written in cups and spoons, this page is the bridge between the two, and the worked examples show the conversion inside real dishes rather than in isolation.
Mayonnaise by the teaspoon is the measure for the small jobs: a spoonful in a sandwich, a spoonful in a dressing, or a spoonful in a single-serve coleslaw. A teaspoon holds 4.58 g, and a cup is 220 g — mayonnaise is a thick emulsion, lighter than water per spoon because it is mostly oil whipped with air. The spoon table is the fastest way to keep a dressing in balance, because the difference between two teaspoons and four is the difference between a light dressing and a heavy one.
All figures on this page are approximate, and they come from USDA, measured spooned and levelled. When a recipe has to work the first time, verify with a kitchen scale.
Conversion table
One teaspoon is one forty-eighth of a cup, so every figure in this table is the cup weight divided by 48, rounded to two decimal places. All figures are approximate; verify with a kitchen scale when it matters.
| Teaspoons | Grams (approx.) |
|---|---|
| 1 tsp | 4.58 g |
| 2 tsp | 9.17 g |
| 3 tsp | 13.75 g |
| 4 tsp | 18.33 g |
| 5 tsp | 22.92 g |
| 6 tsp | 27.50 g |
| 7 tsp | 32.08 g |
| 8 tsp | 36.67 g |
| 9 tsp | 41.25 g |
| 10 tsp | 45.83 g |
| 11 tsp | 50.42 g |
| 12 tsp | 55.00 g |
The tablespoon figures are included too, because most recipes switch between teaspoons and tablespoons, and 3 teaspoons make 1 tablespoon.
| Tablespoons | Grams (approx.) |
|---|---|
| 1 tbsp | 13.8 g |
| 2 tbsp | 27.5 g |
| 3 tbsp | 41.2 g |
| 4 tbsp | 55.0 g |
| 5 tbsp | 68.8 g |
| 6 tbsp | 82.5 g |
| 7 tbsp | 96.2 g |
| 8 tbsp | 110.0 g |
| 9 tbsp | 123.8 g |
| 10 tbsp | 137.5 g |
| 11 tbsp | 151.2 g |
| 12 tbsp | 165.0 g |
| 13 tbsp | 178.8 g |
| 14 tbsp | 192.5 g |
| 15 tbsp | 206.2 g |
| 16 tbsp | 220.0 g |
One tablespoon is one sixteenth of a cup, so every tablespoon figure is the cup weight divided by 16, rounded to one decimal place.
Cups to grams for reference
When a recipe jumps from spoons to cups, use this table instead of counting out 16 tablespoons. Every figure is the cup weight multiplied by the fraction, rounded to one decimal place, and all figures are approximate.
| Cups | Grams (approx.) |
|---|---|
| 1/4 cup | 55.0 g |
| 1/3 cup | 73.3 g |
| 1/2 cup | 110.0 g |
| 2/3 cup | 146.7 g |
| 3/4 cup | 165.0 g |
| 1 cup | 220.0 g |
One cup of mayonnaise weighs 220 g, so a quarter cup is 55.0 g and half a cup is 110.0 g. Those two figures cover most everyday scaling, and the full table above covers the rest.
How the measurement works
The figure on this page comes from USDA, measured spooned and levelled. Emulsified oil, egg and vinegar spread. Sandwiches, dressings, dips and coleslaw.
All results on this page are approximate. Ingredient weights vary with brand, humidity, temperature and how firmly you pack the spoon, so when a recipe has to work the first time, weigh the ingredient on a kitchen scale and use the numbers here as a guide. The method matters more than the number itself, because the same spoon of mayonnaise measured two different ways can give two different weights, and the USDA value assumes the spooned and levelled method every time.
Worked examples
A dressing for a single salad
A dressing for one salad takes 3 teaspoons (13.75 g) of mayonnaise whisked with lemon juice and a little mustard, and the spoon measure keeps the dressing light instead of gloopy. Whisk the lemon juice in first, then the mustard — mayonnaise thins as you whisk, and a dressing made the other way round stays thick and clings in blobs.
Mayonnaise on a sandwich
A sandwich takes 2 teaspoons (9.17 g) of mayonnaise spread thinly on the bread, which is enough to keep the filling moist without making the bread soggy. Spread it edge to edge, because a bare patch lets the filling dry out and a thick patch makes the bread fall apart.
A spoonful in a coleslaw for two
A coleslaw for two takes 6 teaspoons (27.50 g) of mayonnaise tossed with the shredded cabbage and carrot, and the spoon measure keeps the slaw crisp instead of swimming. Add the mayonnaise just before serving, or the salt draws water out of the cabbage and the slaw turns soupy.
Practical guidance
Spoon mayonnaise in level and do not shake the spoon: it is a thick emulsion that holds its shape, so a level spoon is accurate as long as you do not heap it. Light mayonnaise weighs a little less per spoon than full-fat mayonnaise, because it contains more water and air — the difference is a fraction of a gram per teaspoon, so the figures hold for both, but light mayonnaise thins a dressing faster, so add the liquid a little at a time.
Mayonnaise is an emulsion, which means it can split: if it gets too warm, or if you add an acidic ingredient too fast, the oil separates and the dressing turns grainy. Keep mayonnaise refrigerated and use it within two months of opening, and never leave a mayonnaise dressing sitting out — it is the ingredient that food safety guidance worries about most, and for good reason.
Scaling with spoons is easy once you know the weight of one spoon. To measure 100 g of mayonnaise, count out about 21.8 teaspoons, and for 50 g, about 10.9 teaspoons. Halving a recipe that calls for 4 teaspoons means using 2 teaspoons, or 9.17 g, and doubling it means 8 teaspoons, or 36.67 g. The key is to scale every ingredient by the same factor, because changing one ingredient without changing the others throws the recipe out of balance. For large amounts, switch to a cup measure or a scale, since counting out teaspoons one by one is slow and error-prone, and a cup is faster and more accurate.
When should you weigh mayonnaise instead of measuring it? Whenever the recipe has to work the first time, and whenever the amount is large. A kitchen scale costs less than a single failed bake, and it removes the biggest source of variation in home cooking, which is the way ingredients pack into a cup or a spoon. Put the bowl on the scale, press tare, and add the mayonnaise until the display shows the number you need. There is nothing to wash afterwards except the bowl, and the result is the same every time. For small amounts, a level spoon is accurate enough, and for anything where precision matters, the scale is the tool to reach for.
Storage. Refrigerate after opening; use within 2 months.
- Level every spoon with the back of a knife.
- Use spoons for small amounts, and a scale for large ones.
- Keep the same spoon for the whole recipe so errors stay consistent.
Frequently asked questions
How many grams is 1 teaspoon of mayonnaise?
One level teaspoon of mayonnaise weighs approximately 4.58 g. That figure comes from dividing the cup weight of 220 g by 48, and it assumes the ingredient is measured spooned and levelled. All figures on this page are approximate, so verify with a kitchen scale when it matters.
Does light mayonnaise weigh the same as full-fat mayonnaise?
Almost. Light mayonnaise contains more water and air, so it weighs a fraction of a gram less per teaspoon. The difference is smaller than the error from levelling the spoon, so use the same figures for both — but add liquid to a dressing more slowly with light mayonnaise, because it thins faster.
Why does mayonnaise split in a dressing?
Because it is an emulsion of oil and water, and heat or a sudden addition of acid can break it. Add lemon juice or vinegar a little at a time, whisking constantly, and keep the mayonnaise cool. Once split, whisk in a teaspoon of warm water and it will usually come back together.
How long does mayonnaise keep after opening?
About two months in the fridge, sealed. Mayonnaise is the ingredient that food safety guidance worries about most, so do not leave a mayonnaise dressing sitting out at room temperature, and throw away any mayonnaise that smells off or has separated.
How many teaspoons of mayonnaise are in a tablespoon?
There are 3 teaspoons in 1 tablespoon, so 1 tablespoon of mayonnaise weighs approximately 13.8 g, which is three times the teaspoon weight of 4.58 g. Use the tablespoon table on this page when a recipe switches between the two units.
How should I store mayonnaise?
Refrigerate after opening; use within 2 months. Keeping it stored properly also keeps its weight consistent, since an ingredient that has absorbed moisture or dried out will not weigh the same per spoon as a fresh one.