Ingredients: everything doubles, cleanly
At 2×, every ingredient scales linearly — flour, sugar, fat, liquid, salt, leavening, all of it. Baking ratios are proportions, and multiplying the whole recipe keeps every proportion intact. The failure mode isn't chemistry; it's arithmetic done in your head over a mixing bowl. ¾ cup doubled is 1½ cups; 1⅓ cups doubled is 2⅔; "1–2 tbsp" doubles at both ends to "2–4 tbsp". Our scaler does exactly this, fraction-aware:
| Recipe says | Doubled (computed) |
|---|---|
| 2 cups all-purpose flour | 4 cups all-purpose flour |
| 1½ tsp baking powder | 3 tsp baking powder |
| ¾ cup sugar | 1½ cup sugar |
| 1-2 tbsp milk | 2–4 tbsp milk |
Scale yours now
Paste the ingredient list, set 2× (or any factor), and read off the converted lines — ranges, mixed fractions and unit quirks handled. Nothing you paste leaves your browser.
Pans: double the volume, not the pan count in your head
Doubled batter needs double the capacity. Two identical pans is the zero-thought answer — same depth, same bake time, same recipe behaviour. One bigger pan also works if its capacity matches: doubling an 8″ round recipe means 12 cups of capacity, and a 9×13″ pan holds 14 — 2.33× one 8″ round, so the doubled batter fits with sensible headroom. The catch is depth: in the 9×13 the batter sits deeper, so time and temperature shift. The pan converter computes this for any pair you own.
Bake time: the rule people get backwards
Time follows depth, not total quantity. Two 9″ layers side by side bake in the same time as one — the oven doesn't care how many pans it holds, only how thick each one is (give them space; don't stack racks directly). Pour the doubled batter into one deeper pan and the center now has more insulation above and beside it: drop 25°F, plan 15–25% longer, and trust a skewer and 200–210°F internal over the clock.
The edge cases worth knowing
- Eggs. Whole numbers double happily. Halves are why weight wins: a large egg is about 50 g out of the shell — whisk one, pour 25 g, done. (Our scaler can show scaled lines in grams for exactly this reason.)
- Leavening. Fine at 2×, as above. The "reduce the baking powder" folklore belongs to 4×-and-up batches, where one bowl stops mixing evenly — at that point work in batches instead of adjusting chemistry.
- Spices, zest, extracts, salt. Double them, then taste where tasting is safe (doughs, batters without raw flour concerns, fillings). Strong aromatics — cloves, cayenne, almond extract — read slightly louder at scale; adding the last quarter at the end is easier than subtracting.
- Yeast and rise times. Yeast doubles with the flour, but a doubled dough mass holds heat better and can run ahead of the clock. Judge the rise by size (doubled bulk), not minutes. Converting yeast types? The yeast converter handles fresh ↔ active dry ↔ instant.
- Mixing time doesn't double. Creaming butter and sugar takes about as long as it always does; judge by look (pale, fluffy) not by minutes — and check your bowl actually fits double before you start.
Halving works the same way — with one warning
Everything above runs in reverse for ½×, and the scaler handles it (it will print "¼ cup + 2 tbsp" rather than leave you dividing ¾ cup in your head). The one warning: recipes built around a single egg don't halve politely — weigh 25 g of whisked egg, or pick a recipe sized for the batch you want.