Recipe Scaler
Paste the ingredient list, set the servings you have and the servings you want, or pick two pan sizes, and read the scaled list with fractions written the way a recipe would.
Start each line with the amount: 2, 1 1/2, ¾, 2.5
Scaled × 1.5
3 ⅜ cups all-purpose flour 1 ½ tsp baking soda 1 ½ cup butter, softened 4 ½ /4 cup granulated sugar 1 ⅛ cup packed brown sugar 3 large eggs 3 cups chocolate chips salt to taste
Factor
× 1.5
36 ÷ 24
Lines scaled
7
1 left as written
Rounded to
⅛
nearest eighth, as a recipe writes it
Quantities scale linearly. Leavening, salt and spices are usually fine to scale straight; baking time and pan depth are not, so check doneness early when scaling up and expect a thinner bake when moving to a bigger pan.
Pan areas and conversion factors
| Pan | Area (sq in) | From 9" round | From 8" square | From 9 × 13 |
|---|---|---|---|---|
| 8" round | 50 | × 0.79 | × 0.79 | × 0.43 |
| 9" round | 64 | × 1 | × 0.99 | × 0.54 |
| 10" round | 79 | × 1.23 | × 1.23 | × 0.67 |
| 8" square | 64 | × 1.01 | × 1 | × 0.55 |
| 9" square | 81 | × 1.27 | × 1.27 | × 0.69 |
| 9 x 13" rectangle | 117 | × 1.84 | × 1.83 | × 1 |
| 9 x 5" loaf | 45 | × 0.71 | × 0.7 | × 0.38 |
| Half sheet 13 x 18" | 234 | × 3.68 | × 3.66 | × 2 |
| 10" bundt (12 cup) | 100 | × 1.57 | × 1.56 | × 0.85 |
Common factors and what ¾ cup becomes
| Change | Factor | ¾ cup → | 1 ½ tsp → | 2 eggs → |
|---|---|---|---|---|
| Halve (4 → 2) | × 0.5 | ⅜ cup | ¾ tsp | 1 |
| 4 → 6 | × 1.5 | 1 ⅛ cup | 2 ¼ tsp | 3 |
| Double (4 → 8) | × 2 | 1 ½ cup | 3 tsp | 4 |
| 6 → 8 | × 1.333 | 1 cup | 2 tsp | 2 ⅝ |
| 8 → 12 | × 1.5 | 1 ⅛ cup | 2 ¼ tsp | 3 |
| 12 → 16 | × 1.333 | 1 cup | 2 tsp | 2 ⅝ |
| Triple | × 3 | 2 ¼ cup | 4 ½ tsp | 6 |
The scaler rounds to the nearest eighth, which is the smallest measure most kitchens have. If a scaled amount lands on something odd, like ⅝ cup, measure ½ cup plus 2 tablespoons. For bread and pastry, scaling by weight is more exact; the baker's percentage tool on this site does that.
Frequently Asked Questions
How do I scale a recipe?
Divide the servings you want by the servings the recipe makes to get a factor, then multiply every ingredient by it. A recipe for 4 scaled to 6 is × 1.5: 2 cups of flour becomes 3, ¾ teaspoon of salt becomes 1⅛. The scaler parses the number at the start of each line, including fractions like 1 1/2 and ¾, and rewrites it to the nearest eighth.
How do I convert a recipe to a different pan?
Scale by area, not by the pan's name. A 9-inch round is 63.6 square inches; a 9 × 13 rectangle is 117, so the factor is 1.84. Choose the two pans above and the scaler does the arithmetic. Keep the batter depth similar or the bake time changes a lot; a deeper pan needs a lower oven and longer.
Does everything scale in a straight line?
Ingredients do. Time and temperature do not: a doubled cake in a bigger pan of the same depth bakes in about the same time, while a doubled cake in the same pan takes much longer and may sink. Leavening scales fine in normal ranges; when going 4× or more, some bakers trim baking powder slightly. Salt and spices are safe to scale straight and adjust at the end.
What about eggs?
Round to the nearest whole egg for small changes (1.5× a two-egg recipe is three eggs). For awkward factors, beat an egg and measure it: one large egg is about 50 g or 3 tablespoons, so half an egg is 1½ tablespoons.
These tools use baker's percentages, salt-by-weight brining, coffee ratios by weight and the USDA roasting and thawing tables, all stated on each page. They are starting points for your kitchen, your flour and your oven: taste the brine, watch the dough, and always cook poultry to 165°F on a thermometer.