Recipe Scaler

Scaling is a ratio — the skill is the rounding

Every ingredient is multiplied by target servings ÷ original servings. Doubling a recipe is trivial arithmetic; the hard part is what to do with "0.83 eggs" or "1.66 cups." Our scaler rounds to the fractions on your measuring cups and spoons — ⅛, ¼, ⅓, ½, ⅔, ¾ — and, above 10 units, to halves. You get "1½ cups," never "1.537 cups."

What doesn't scale linearly

Ingredients scale; cooking behavior doesn't. When you scale up:

• Spices and salt: start at 75–80% of the scaled amount and adjust at the end — seasonings intensify in bigger batches.
• Cook time: a doubled casserole needs longer, not double — think +25–50% with a thermometer or knife-test to confirm.
• Pan size: doubling a recipe means more pan area or two pans. Use our cake pan converter to check the fit.
• Baking powder / yeast: scale cautiously (round down); leavening is chemistry, not seasoning.

Scaling down works the same way

Cooking for two from a four-serving recipe? The same ratio logic applies in reverse. For baking specifically, halving eggs is the awkward case — beat the egg, then weigh it, and use half by weight (a large egg ≈ 50 g out of the shell).