Recipe Nutrition Calculator

How the calculator works

Recipe nutrition is bookkeeping. For every line of the recipe, the calculator does four things:

1. Reads the amount and unit. “2 cups all-purpose flour” becomes 2, cups, all-purpose flour.
2. Matches the food. It looks for the longest name it knows in the line, so “brown sugar” is matched as brown sugar and not as sugar.
3. Converts to grams. Weights are used as given. Volumes use the USDA weight for a cup of that food. Counted items use the USDA weight of one: 50 g for a large egg, 110 g for a medium onion.
4. Multiplies. USDA lists nutrients per 100 g, so the line’s share is grams / 100 x the value.

nutrient in a line = grams / 100 x nutrient per 100 g

per serving = sum of all lines / servings

Open “Show the math” under the result to see every line with its weight.

Worked example

A plain butter cake: 2 cups all-purpose flour, 1/2 cup butter, 3/4 cup sugar, 2 eggs, 1 teaspoon baking powder, 1/2 cup milk and 1/4 teaspoon salt, cut into 12 pieces.

Ingredient	Weight	Calories
2 cups flour	250 g	910
1/2 cup salted butter	113.5 g	814
3/4 cup sugar	150 g	581
2 large eggs	100 g	143
1/2 cup whole milk	122 g	74
1 tsp baking powder	4.6 g	2
1/4 tsp salt	1.5 g	0

The total is 2,524 calories. Divided by 12, that is 210 calories a piece, with 9 g of fat, 29 g of carbohydrate, 13 g of sugars, 3.6 g of protein and 167 mg of sodium.

Three ingredients carry 91 percent of the calories: the flour, the butter and the sugar. That is the usual pattern in baking, and it tells you where a change would matter. Leaving out the salt changes nothing in the calorie column.

Reading the result against Daily Values

The FDA sets Daily Values for use on nutrition labels. For the nutrients this calculator reports, they are:

• Total fat: 78 g
• Saturated fat: 20 g
• Cholesterol: 300 mg
• Sodium: 2,300 mg
• Total carbohydrate: 275 g
• Dietary fiber: 28 g
• Protein: 50 g

The FDA’s rule of thumb for reading a label is that 5 percent of the Daily Value or less per serving is considered low, and 20 percent or more is considered high.

For the cake above: 5.3 g of saturated fat is 27 percent of 20 g, which counts as high. 167 mg of sodium is 7 percent of 2,300 mg. 0.6 g of fiber is 2 percent of 28 g, which is low.

There is no Daily Value for total sugars. The FDA’s 50 g figure is for added sugars only, and the USDA records this calculator uses report total sugars, so the two cannot be compared directly.

Where the numbers can be off

Brands. USDA values are averages for a type of food. Your butter or your soy sauce may differ, sometimes by a lot for sodium.

How you measure. A cup of flour is 125 g in the USDA record used here. A cup scooped straight from the bag can weigh more. If you have a scale, enter grams.

Counted items. One onion is taken as 110 g and one potato as 213 g, the USDA medium sizes. The same USDA records put a large onion at 150 g and a large potato at 369 g.

What is left behind. Oil left in the frying pan, marinade poured away and salted pasta water are in the total even though you did not eat them.

Missing values. A few USDA records have no figure for one nutrient. Total sugars are blank for ground pork, firm tofu and canned coconut milk, for example. The calculator counts a blank as zero.

Lines not counted. Anything listed under “Not counted” adds nothing. If that is a main ingredient, the total is too low.

Writing lines the calculator can read

• Put the amount first: “200 g chicken breast”, not “chicken breast, 200 g”.
• Use grams, ounces, pounds, cups, tablespoons or teaspoons.
• For meat, fish and anything else sold by weight, give a weight. USDA has no cup weight for ground beef.
• Replace “1 can” or “1 package” with what it weighs.
• “Salt to taste” cannot be counted. If sodium matters to you, measure the salt once and enter it.

Tips and common mistakes

Check the servings figure first. Halving the number of servings doubles every result, and it is the easiest input to get wrong.

Use “butter” for salted butter and “unsalted butter” when that is what you use. The difference is 632 mg of sodium per 100 g.

Read the “Not counted” list every time.

Compare versions of a recipe instead of chasing an exact figure. Swapping one ingredient and seeing what moves is where this kind of calculator is most reliable.

Weigh the finished dish if you want a per 100 g figure for leftovers: divide the totals by the cooked weight.