How to Convert Grandma's Recipes: Old Measurements, Grams, Cups and Modern Baking

To convert grandma’s recipe, copy the original first, then convert one ingredient at a time using that ingredient’s own grams per cup value: a US cup of all-purpose flour is 120 grams (g), a cup of granulated sugar is 200 g, and a cup of butter is 227 g. Vague measures such as “a pinch” or “a moderate oven” have no exact modern equivalent, so treat them as starting estimates and confirm them with a test bake. The goal is a modern version that bakes like the original, not a set of numbers that only looks precise.

This guide covers how to read old wording, which cup the cook was probably using, why flour causes the largest errors, and how to write a standardized version your family can repeat. A full worked conversion of a handwritten cookie card is in the middle of the article.

Why old family recipes are hard to follow

Handwritten recipes were usually reminders for someone who already knew the dish. The cook knew what the dough should feel like, which oven ran hot, and which cup lived in the flour bin. The card only needed enough detail to jog that memory.

That creates 5 common problems when someone else tries to follow it:

1. Missing amounts. Ingredients such as salt, vanilla, or flour may be listed with no quantity, or with “enough to make a soft dough”.
2. Household measures. A teacup, a coffee cup, or “butter the size of an egg” depended on the objects in that kitchen.
3. Unstated cup standards. A card from the UK or Australia may use a different cup from a card written in the US.
4. Old ingredient names. Terms such as oleo, sweet milk, or a cake of yeast need translating before they can be measured.
5. No oven temperature. Many older recipes describe heat as slow, moderate, or hot, and some give no temperature or time at all.

None of these problems has a single correct answer. The practical approach is to make reasonable, recorded choices and let a test bake tell you what to adjust.

Start by preserving the original

Before changing anything, keep an unchanged copy of the recipe. Photograph or scan both sides of the card, including stains and margin notes. Notes such as “double for Christmas” or “use the blue cup” often explain how the recipe was really made.

Then type out a transcription exactly as written, including spelling and abbreviations. Mark anything you cannot read with a question mark rather than a guess. Keep this transcription separate from your converted version, so later readers can see which parts came from the card and which parts you decided.

Informal measures: pinch, dash, handful, and teacup

Old recipes often use measures that were never standardized. The interpretations below are commonly used starting points, not historical facts. Each kitchen’s teacup, handful, and egg was different.

Two approaches reduce the guesswork:

• Measure the actual object when it still exists. If grandma’s teacup is in the cupboard, fill it with water, pour the water into a liquid measuring cup, and write down the volume. That single measurement is more reliable than any table.
• Weigh your own handful. For a handful of nuts or raisins, grab one handful three times and weigh or measure each. The average is a reasonable starting point for your version.

For butter “the size of an egg”, ¼ cup of butter is approximately 57 g (227 ÷ 4). Treat this as a first try and adjust by feel if the dough looks dry or greasy.

Cups, spoons, and ounces in older recipes

Clear amounts such as “1 cup” or “2 tablespoons” are easier to convert, but you still need to know which system the cook used.

Which cup was the cook using?

Cup sizes differ by country and era:

• US customary cup: 236.6 milliliters (ml). This is the default for this site and for most American family recipes.
• Metric cup: 250 ml, used in Australia, New Zealand, Canada, and South Africa.
• Old British imperial cup: half an imperial pint, about 284 ml.

The difference grows with density and quantity. A 250 ml metric cup of all-purpose flour, filled the same way, holds approximately 127 g (250 × 120 ÷ 236.6). An imperial cup would hold approximately 144 g. If a recipe from a British relative lists 3 cups of flour, the choice of cup can change the flour by more than 70 g.

Look for clues: an Australian recipe book, metric temperatures, or a note in grams elsewhere on the card suggests a metric cup. Tablespoons need the same check, since an Australian tablespoon holds 20 ml against approximately 15 ml for a US tablespoon.

Ounces and pounds: weight or volume?

Older recipes, especially British ones, often give dry ingredients in ounces (oz) and pounds (lb). For flour, sugar, and butter, these are weights. One ounce is 28.35 g and one pound is 453.6 g. So “½ lb flour” is approximately 227 g, and “¼ lb butter” is approximately 113 g.

Liquids are different. “8 oz milk” in a US recipe usually means 8 fluid ounces, which is 1 US cup. When a card lists ounces for a liquid, assume volume unless the recipe is clearly written for a scale.

Converting each ingredient to grams

A cup is a volume, and grams are a weight. Each ingredient packs into a cup differently, so no single number converts every ingredient. The method is the same for each line of the recipe:

Grams = cups × grams per cup for that ingredient.

Useful values for common family baking recipes, all per level US cup:

• All-purpose flour: 120 g (spoon and level)
• Granulated sugar: 200 g
• Brown sugar, packed: 220 g
• Butter: 227 g
• Milk: 240 g

For small spoon amounts, divide the cup value by 16 for tablespoons or 48 for teaspoons. One teaspoon of baking soda is approximately 4.6 g (220 ÷ 48).

If you want the reasoning behind this method, including why water cannot serve as a universal conversion basis, the guide on how to convert grams to cups explains ingredient density with worked examples. For a single ingredient, the grams to cups converter gives the number directly.

Eggs, vanilla, and leaveners measured by the teaspoon can stay as they are in the modern version. Converting “2 eggs” to grams is only useful if you plan to use a different egg size from the original cook.

Flour: the largest source of error

Flour is where converted family recipes most often go wrong. This site’s 120 g per cup value assumes the flour is spooned into the cup and leveled, and King Arthur Baking’s ingredient weight chart also lists a cup of all-purpose flour at 120 g. Many home cooks, past and present, dip the cup straight into the flour bin instead. This site estimates that scooping adds 20 to 30 g per cup of all-purpose flour compared with spoon and level.

That means grandma’s cup of flour may have weighed 140 to 150 g, not 120 g. Across 3 cups, the gap is 60 to 90 g, about 17% to 25% more flour than a spoon-and-level conversion gives.

You usually cannot know which method she used, but the card and the family can offer clues:

• Ask relatives how she measured. Someone may remember a scoop in the flour canister.
• Read the texture notes. “Stiff dough” or “roll thin” can suggest more flour than a soft, spooned amount.
• Compare the ratio with a similar modern recipe. If her cookie dough seems to have far less flour than typical recipes, she may have been scooping.

A practical approach is to start at 120 g per cup, then hold back and add flour if the dough is too soft. Write down the final amount you used. The comparison of spoon and level vs scoop and sweep explains how the two fill methods differ.

Butter, oleo, and other old fats

Butter lines in family recipes appear in several forms: cups, sticks, pounds, tablespoons, or household comparisons. A US stick is 8 tablespoons, ½ cup, or 113.5 g on this site. A pound of butter is 4 sticks.

Older American recipes may say oleo, which means margarine. British cards may list lard, dripping, or suet. These fats contain different amounts of water and fat, so they do not always behave like butter even at the same weight. Use the fat the card names when you can find it, or note the substitution in your modern version.

State matters too. “1 cup butter, melted” means measure solid butter, then melt it. “Butter, softened” matters for creamed cakes and cookies. If the card does not say, look at the method: creaming with sugar needs softened butter, while a mixture stirred in a saucepan uses melted butter. For measuring techniques when you have no scale, see how to measure butter without a scale.

Old oven terms: slow, moderate, and hot

Before ovens had reliable thermostats, recipes described heat with words. Modern cooking references commonly translate those words into the approximate ranges below. Sources do not fully agree, and some older publications give wider or different ranges, so treat these as starting points only.

For a first test, choose a temperature inside the range that suits the item. Cookies and cakes described as “moderate oven” often start well at 350°F (about 175°C). Check for doneness early, since cards rarely give a reliable time and your oven may run hotter or cooler than hers.

Worked example: converting a handwritten sugar cookie card

The card below is a typical example of the kind of recipe families keep. It is used here to show each conversion step.

The original card

Sugar Cookies

• 1 c. butter or oleo
• 1½ c. sugar
• 2 eggs
• 1 tsp vanilla
• 3 c. flour
• 1 tsp soda
• 2 tsp cream of tartar
• pinch salt

Roll in sugar. Bake in moderate oven till just set.

Step 1: identify the cup and the ingredients

The abbreviations “c.” and “tsp” and the word “oleo” suggest an American recipe, so the conversion uses US cups. “Soda” means baking soda. “Sugar” without a qualifier means granulated sugar.

Step 2: convert each measured ingredient

• Butter: 1 cup × 227 g = 227 g (2 US sticks).
• Sugar: 1.5 cups × 200 g = 300 g.
• Flour: 3 cups × 120 g = 360 g, spoon and level. If grandma scooped, her flour may have been 420 to 450 g (3 × 140 to 150 g).
• Baking soda: 1 teaspoon × 4.58 g = approximately 4.6 g.
• Eggs, vanilla, and cream of tartar: keep as written. Use large eggs unless the family remembers otherwise.

Step 3: decide on the vague items

• Pinch of salt: start with ⅛ teaspoon of table salt, which is approximately 0.8 g (288 ÷ 48 ÷ 8). Taste the raw dough if you are comfortable doing so, or adjust in the next batch.
• Moderate oven: start at 350°F (about 175°C).
• “Till just set”: check the first tray early and write down the time that gives the texture the family remembers.

Step 4: test and adjust the flour

Mix the dough with 360 g of flour first. If it is too soft to roll into balls, add flour 15 to 20 g at a time until it holds its shape, and record the total.

The standardized modern version

The card assumed the baker would cream butter and sugar, add eggs and vanilla, then add dry ingredients. The modern version should spell that out, as shown in the next section.

A short British example

A card reading “½ lb flour, ¼ lb butter, a teacup of milk” converts differently. The first two lines are weights: approximately 227 g flour and approximately 113 g butter. No cup conversion is needed. The teacup is the uncertain line. If the original cup is gone, start with about ¾ US cup (approximately 177 ml) of milk, add it gradually, and stop when the dough reaches the texture the card describes.

Reading handwriting and filling gaps

Handwritten numbers cause their own errors. Check these common mix-ups before converting:

• 1 and 7, since a 1 written with a long upstroke, common in European handwriting, can look like a 7.
• ½ and ⅓, which can blur on a stained card.
• T and t, where a capital T usually means tablespoon and a lowercase t means teaspoon.
• “c” and “oz”, which can look similar in quick handwriting.

When a number looks wrong, test it against the recipe’s ratios. A cookie recipe with 1 tablespoon of baking soda to 3 cups of flour would be unusual; 1 teaspoon is more likely. Record your reading and the reason for it, so the next person knows it was an interpretation.

Writing a standardized modern version

A good modern version keeps the original’s character while removing guesswork. Include these 6 parts:

1. Ingredient names with state: “butter, softened”, “flour, spooned and leveled”, “brown sugar, packed”.
2. Weights in grams, with the cup or spoon amount in parentheses for cooks without a scale.
3. Numbered method steps that describe what the original cook did from memory.
4. Oven temperature and a time range, plus a doneness cue such as “edges just set”.
5. Yield, such as the number of cookies or the pan size.
6. A notes section listing every assumption: which cup, flour method, how you read unclear numbers, and changes after testing.

Keep the original card image and transcription alongside the modern version. The two together make the recipe both usable and traceable. For general measuring habits to use when you test, the guide on how to measure baking ingredients covers scales, cups, spoons, and liquids.

Scaling a converted family recipe

Grams make scaling simpler, because every ingredient multiplies by the same factor. For 1½ batches of the sugar cookies above:

• Butter: 227 × 1.5 = 340.5 g, about 341 g
• Sugar: 300 × 1.5 = 450 g
• Flour: 360 × 1.5 = 540 g
• Baking soda: 4.6 × 1.5 = approximately 6.9 g, or 1½ teaspoons
• Eggs: 2 × 1.5 = 3 eggs

Eggs, pans, and baking times do not always scale neatly. When the math gives a fraction of an egg, beat the egg and measure part of it, or round and accept a small texture change. Larger batches in a bigger pan may need a different baking time. The recipe scaler multiplies every line for you once the recipe is in consistent units.

When not to guess

Some parts of a family recipe should not be filled in by estimate alone:

• Canning and preserving recipes. Old home canning methods may not meet current safety guidance. Use a tested modern recipe for anything sealed in jars, and keep grandma’s card for the flavor ideas.
• Leavening that looks unusual. If baking soda or baking powder seems very high or very low, compare the recipe with a similar modern one before baking.
• Ingredients you cannot identify. Ask relatives or look up the term before substituting. A wrong guess about an ingredient can change the recipe far more than a measuring error.
• Recipes the family remembers clearly. If someone knows how the dish should look and taste, bake it with them. Their memory is better evidence than any conversion table.

For everything else, convert carefully, test once, write down what you changed, and repeat. After two or three bakes, the modern version usually settles into a recipe that matches the family memory closely.