Here is the answer up front: 312 g of corn syrup is about 1 cup. The figure comes from 312 g per cup (poured, King Arthur Baking) and the division 312 ÷ 312. Glucose syrup that stays liquid and prevents crystallisation. You will meet corn syrup in candy, pecan pie filling, frostings and sauces, and if you cook from recipes written in grams, this direction of the conversion is the one you will use most. This page keeps it practical: a table you can read at a glance, three worked examples, the method behind the number, and answers to the questions that come up when grams and cups share a kitchen.
Full conversion table
This table is the working heart of the page. One cup of corn syrup weighs 312 g (poured, King Arthur Baking), and each row divides the gram weight by that figure. Results are rounded to a sensible cup measure and are approximate: use them as measuring targets, and let the scale have the last word when the bake matters.
| Grams | Cups (approx.) |
|---|---|
| 25 g | 0.08 cups |
| 50 g | 1/6 cup |
| 75 g | 1/4 cup |
| 100 g | 1/3 cup |
| 150 g | 1/2 cup |
| 200 g | 5/8 cup |
| 250 g | 4/5 cup |
| 300 g | 0.96 cups |
| 312 g | 1 cup |
| 400 g | 1 2/7 cups |
| 500 g | 1 3/5 cups |
The table rounds cup figures to the nearest useful fraction or to two decimals, and that rounding is honest: a kitchen cup cannot meaningfully distinguish 0.42 cups from 0.44 cups in a recipe that also depends on oven temperature, humidity and the age of the ingredients. Do not chase the last hundredth. What matters is being in the right neighbourhood — about one cup for 312 g rather than a packed cup that quietly held far more — and the table puts you there every time.
How 312 g works in practice
Example 1 — grams in, cups out
A recipe lists 312 g of corn syrup. The conversion is one division: 312 ÷ 312 = 1 cup. Measure the cup poured. That is the whole technique, and it is worth doing properly because a recipe that is converted carefully is a recipe that behaves the way its writer intended — while a recipe converted by guesswork is a new recipe, untested.
Example 2 — the two-cup scale-up
When the recipe grows to 624 g, the answer is 2 cups. Weigh 624 g into a tared bowl if you can; if you must use cups, fill two level cups poured and check them against the scale if one is handy. Recipes built around this quantity are usually batch recipes (candy, pecan pie filling, frostings and sauces), and batch recipes punish inaccuracy more than small ones do.
Example 3 — the awkward in-between weight
Suppose a recipe asks for 150 g of corn syrup. That is 1/2 cup (150 ÷ 312). Measure a cup, remove about 162 g — roughly 1/2 cup of a cup — or simply weigh 150 g and skip the cups altogether. The table on this page exists for exactly these in-between weights, where guessing is tempting and wrong.
Source, method and the honest caveats
Two facts sit behind every number here. First, the source: King Arthur Baking, which lists one cup of corn syrup at 312 g. Second, the method: poured. Together they define the cup this page is talking about. Change either one and the numbers shift — which is exactly what happens when a recipe from another source quotes a different weight for the same ingredient. It is usually measuring a different cup. There is no famous dispute about the weight of corn syrup: the figure used here is stable across the sources we checked, which is one reason this conversion is reliable. Even so, every figure on this page is labelled approximate, because how full the cup is, how settled the ingredient is, and the temperature in your kitchen all move the number a little. When precision matters, verify with a kitchen scale.
Making the conversion work in a real kitchen
A real kitchen is not a laboratory, so here is the practical version. Weigh corn syrup when the recipe is a bake or a batch you want to repeat; measure by cup when it is a soup, a sauce or a weekday dish where a few grams either way will not show. Keep your measuring cups honest — a dented cup or a mismatched set is a quiet source of error — and keep the ingredient itself in good shape: Airtight container at room temperature, up to 1 year. Fresh, dry and properly stored, corn syrup weighs what the table says it weighs.
Bigger batches, smaller batches
Batch size is a choice, and weight is what makes the choice easy. From 312 g (1 cup), a half batch is 156 g (1/2 cup), a quarter batch is 78 g (1/4 cup), a double batch is 624 g (2 cups), and a triple batch is 936 g (3 cups). The division never changes — grams ÷ 312 — so the only new thinking is practical. Large batches need large bowls, large tins and longer bakes, and the baking time grows by roughly a quarter rather than tripling, so test with a skewer and watch the colour. Small batches need small tins and shorter bakes, and they are the ones that catch people out, because a small cake in a hot oven goes from done to dry in minutes. Scale the salt and raising agents with everything else, weigh every scaled amount instead of estimating it, and write the scaled figures on the recipe before you start. A recipe that is scaled on paper and weighed on a scale is a recipe you can make at any size, any number of times, with the same result.
Frequently asked questions
How many cups is 312 g of corn syrup?
312 g of corn syrup is 1 cup (approximately). One cup weighs 312 g (poured, King Arthur Baking), so the calculation is 312 ÷ 312. The figure is approximate, so verify with a kitchen scale when precision matters.
How many grams is 1 cup of corn syrup?
One cup of corn syrup weighs 312 g, poured, according to King Arthur Baking. That is the anchor figure for every conversion on this page: divide any gram weight by 312 to get cups, or multiply any cup amount by 312 to get grams.
Can I measure 312 g of corn syrup without a scale?
Yes — measure one cup with a dry measuring cup, spooning the corn syrup in loosely and levelling it off with a straight edge. Do not scoop with the cup and do not pack it unless the method says packed. A careful cup lands close to 312 g, which is good enough for everyday cooking, though a scale is better for baking.
Why do different websites give different weights for corn syrup?
Because they measure the cup differently. King Arthur Baking lists 312 g per cup poured, while other sources may scoop, sift or pack, and each method gives a different weight. The ingredient itself has not changed — only the measuring method has. Match the method and the numbers agree.
How many tablespoons is 312 g of corn syrup?
One tablespoon of corn syrup weighs about 19.5 g, so 312 g is about 16 tablespoons — which is 16, the number in a cup, as expected. Tablespoons are useful for small adjustments, but for a full cup, weighing or using a cup measure is more accurate than counting spoonfuls.
What if my recipe calls for 250 g of corn syrup?
250 g is 4/5 cup (250 ÷ 312). Measure one cup and add about -62 g more, or weigh 250 g directly — which is easier and more accurate. The table on this page covers 25 g to 500 g for exactly these in-between weights.