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 cups 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. Then check depth, because depth sets the bake: doubled batter in a 9×13 sits about 0.99″ deep, against about 1.15″ in one 8″ round. Batter depth is similar in both pans. Keep the oven temperature: bake time should be close to the original; start testing 5 minutes early. 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 pan where it sits meaningfully deeper and the center now has more insulation above and beside it. Our pan converter's rule of thumb for that case: lower the oven 25°F and increase bake time roughly 15–25% (an estimate, not a published or tested figure); start testing at the original time. Either way, trust a skewer over the clock. (The 9×13 above isn't that case — its doubled batter is no deeper than the original layer.)
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 (King Arthur's weight chart) — whisk one, pour 25 g, done. (Our scaler can show scaled lines in grams for exactly this reason.)
- Leavening. Fine at 2×, as above. Advice to cut baking powder only comes up for much bigger scale-ups, and we found no published reduction to quote. Past 3× the recipe scaler warns: mix in rounds of 3× or less, or bake a test batch and adjust leavening, salt and spices to taste.
- Spices, zest, extracts, salt. At 2×, double them with everything else. Strong aromatics — cloves, cayenne, almond extract — are easier to add than to take out, so if a recipe is new to you, note how the doubled batch tastes and adjust next time.
- 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: ¾ cup sugar halves to "⅜ cup sugar" (that's ¼ cup plus 2 tablespoons), so you're never dividing 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.