Recipe scaler
Paste your ingredient list, then say how many it serves and how many you want. Every amount is multiplied, awkward fractions become cups and spoons you can measure, and the arithmetic sits under each line. Lines with no amount, like “salt to taste”, stay as written.
For 6 servings
6 ÷ 4 = 1 1/2, so every amount is multiplied by 1 1/2.
7 lines scaled. 1 line kept as written: its note says why.
2 1/4 cups all-purpose flour
1 1/2 cups × 1 1/2 = 2 1/4 cups.
3 tbsp sugar
2 tbsp × 1 1/2 = 3 tbsp.
5 1/4 tsp baking powder
3 1/2 tsp × 1 1/2 = 5 1/4 tsp.
3/8 tsp salt
1/4 tsp × 1 1/2 = 3/8 tsp.
1 3/4 cups + 2 tbsp milk
1 1/4 cups × 1 1/2 = 1 7/8 cups.
1 1/2 large eggs
1 × 1 1/2 = 1 1/2. Use 1 egg, then beat 1 more and use half of it.
4 1/2 tbsp butter, melted
3 tbsp × 1 1/2 = 4 1/2 tbsp.
Butter for the pan
No amount on this line, so it stays as written.
Cooking more? Times and temperatures don’t multiply, and the food needs 1 1/2 times the room: check what your pan holds.
How recipe scaling works
Divide the servings you want by the servings the recipe makes. That number, the scaling factor, multiplies every amount. For 6 servings from a recipe for 4, 6 ÷ 4 = 1 1/2, so 1 1/2 cups of flour becomes 1 1/2 × 1 1/2 = 2 1/4 cups.
The scaler multiplies exact fractions and rounds only at the end, to the cups and spoons in a standard set. Half of 1/3 cup is 1/6 cup, which no measuring cup holds, so it reads 2 tbsp + 2 tsp. Scaling 2 quarts by 3/5 gives 1.2 quarts, which is 4.8 cups.
What the arithmetic can’t scale
Times and temperatures. A bigger batch or a deeper pan can take longer to cook through, so check for doneness instead of multiplying the time.
Pan size. Scaled up by 1 1/2, the batter or stew needs 1 1/2 times the room. Measure what your pan holds with the pan capacity calculator.
Part of an egg. Whisk one egg and use the share the scaler gives, such as half of it.
Weighing. Cup measures drift as a batch grows; grams don’t. To weigh instead, convert cups to grams by ingredient.
Common amounts, halved to doubled
Each answer is a measure from a standard US set of cups and spoons. Scroll sideways to see every column.
| Amount | Half | A third | 1 1/2 times | Double |
|---|---|---|---|---|
| 1/4 cup | 2 tbsp | 1 tbsp + 1 tsp | 1/4 cup + 2 tbsp | 1/2 cup |
| 1/3 cup | 2 tbsp + 2 tsp | about 1 tbsp + 2 1/4 tsp | 1/2 cup | 2/3 cup |
| 1/2 cup | 1/4 cup | 2 tbsp + 2 tsp | 3/4 cup | 1 cup |
| 2/3 cup | 1/3 cup | about 3 tbsp + 1 3/4 tsp | 1 cup | 1 1/3 cups |
| 3/4 cup | 1/4 cup + 2 tbsp | 1/4 cup | 1 cup + 2 tbsp | 1 1/2 cups |
| 1 cup | 1/2 cup | 1/3 cup | 1 1/2 cups | 2 cups |
| 1 tbsp | 1/2 tbsp | 1 tsp | 1 1/2 tbsp | 2 tbsp |
| 1 tsp | 1/2 tsp | about 3/8 tsp | 1 1/2 tsp | 2 tsp |
Lines the scaler keeps as written
When a line could be read two ways, the scaler leaves it alone and says why, rather than guess. Edit the line in the box and it scales.
| Line | What the scaler does |
|---|---|
| Salt to taste | Keeps it: there’s no amount to multiply. |
| 1 to 2 tsp salt | Keeps the range and shows both ends multiplied. |
| 2 (14-ounce) cans tomatoes | Keeps the can size and says how many cans you need. |
| Bake for 20 minutes | Keeps it: times and temperatures don’t multiply. |
| 1 T oil | Asks for tbsp or tsp, because T and t are easy to mix up. |
| 1 metric cup flour | Keeps it: a metric cup is 250 mL, more than a US cup’s 236.6 mL. |