Kitchen conversions

1 cup all-purpose flour ≈ 125 g

1 cup of all-purpose flour weighs 125 g; 1 tbsp 7.8 g; 1 tsp 2.6 g.

1 cup = 16 tablespoons

US measures: 3 tsp = 1 tbsp, 16 tbsp = 1 cup, 2 cups = 1 pint, 4 cups = 1 quart. A metric cup is 250 ml; an Australian tablespoon is 20 ml.

8 ounces = 227 grams

1 oz = 28.35 g; 1 lb = 16 oz = 453.6 g. Weight ounces are not fluid ounces: a cup of flour weighs about 4.4 oz.

350°F = 175°C

Oven dials go in steps, so we round to the nearest 5 degrees (many charts round 175°C up to 180°C; either works).

Convection (fan) oven: set it about 25°F (15°C) lower, or keep the temperature and start checking 5 to 10 minutes early. Ovens vary; an oven thermometer tells you what yours really does.

9x13-inch rectangle → 8x8-inch square: about ½ of the recipe (×0.55)

Worked out by area, so the batter stays about as deep as in the original pan.

Not scaling? The batter would be 1.8 times as deep, so it needs longer: lower the oven 25°F and cover loosely with foil if the top browns first.

Bake time follows depth more than size: use the recipe's doneness cue (a toothpick, the wobble, the color), not the clock. Capacities are filled to the rim; sloped sides hold a little less.

Glass and ceramic heat up more slowly than metal, then hold the heat, so batter in them often takes longer to bake and the edges can overbake before the middle is done. For glass, King Arthur Baking's advice is to lower the oven 25°F and allow up to 10 minutes more. Dark metal browns the most, so watch the edges.

3 large eggs ≈ 3 medium eggs plus about 1 tbsp beaten egg

USDA sizes are minimum weights per dozen, so eggs in one carton vary. For baking, beat the eggs and weigh or measure: a large egg is about 50 g (3 ¼ tbsp) without the shell.

1 packet active dry = 5.6 g instant (rapid-rise) or 17 g fresh (cake)

Our rule of thumb, not a lab number: brands differ and dough temperature matters more, so watch the rise, not the clock. Many bakers swap instant and active dry one for one; ours uses a little less instant.

Active dry: dissolve it in warm water (about 105 to 110°F) first. Instant: mix it straight into the flour. Fresh: crumble it into lukewarm liquid; it keeps about 2 weeks in the fridge.