Converting Grandma's Recipes to Modern Measurements

Family recipe cards are full of charm and short on precision: “a cup of flour,” “a knob of butter,” “sugar to taste.” Converting them to grams can make them easier to reproduce reliably, as long as you’re thoughtful about what you’re actually converting.

Start with the measurable instructions

Anything given as a clear cup or spoon amount converts directly: a cup of flour becomes about 120g, a cup of sugar becomes about 200g, a tablespoon of butter becomes about 14g. Run each ingredient through its own density using the converter rather than a single blanket ratio, exactly as you would with any modern recipe.

Handle the vague instructions separately

For amounts like “a handful” or “to taste,” resist the urge to invent a precise number. That vagueness was often intentional, adjusted by the original cook based on how the dish looked or tasted in the moment. Make your best estimate, note it down, and adjust after the first attempt rather than treating a guess as gospel.

Watch for regional cup sizes

Older recipes, especially those from outside the US, may have been written using a metric or Imperial cup rather than the US customary cup this site uses by default. If a family recipe originated in the UK, Australia, or continental Europe, double-check which cup standard was likely in use before converting; the difference compounds across a recipe with several cup measurements. How to Measure Ingredients for Baking covers the full table of cup standards by country if you’re not sure which one a card was written against.

Keep a record as you go

The most useful thing you can do while converting a family recipe is write down the gram equivalents directly on the card (or in a note) once you’ve settled on them, rather than reconverting from memory every time. That turns a one-time conversion effort into a permanent upgrade to a recipe that might otherwise stay approximate forever. King Arthur Baking’s ingredient weight chart is a useful cross-check if a family recipe’s cup amount seems unusually high or low for what you’d expect.