Recipe scaler
Paste an ingredient list, enter how many servings the recipe makes and how many you need, and every amount is scaled for you in fractions you can actually measure.
It reads “1 1/2”, “1½”, “1-2”, decimals and lines with no unit, like “3 eggs”. Pinches, dashes and anything “to taste” are left alone.
One ingredient per line, amount first.
Servings, cookies, muffins: use whatever the recipe counts.
Scaled ×0.5
- 1⅛ cups all-purpose flourMeasure as 1 cup + 2 tbsp
- ½ tsp baking soda
- ¼ tsp salt
- ½ cup butter, softened
- ⅜ cup granulated sugarMeasure as ¼ cup + 2 tbsp
- ⅜ cup packed brown sugarMeasure as ¼ cup + 2 tbsp
- 1½ large eggsMeasure as about 75 g beaten egg
- ½-1 tsp vanilla extract
- 1 cup chocolate chips
- Flaky salt, to taste
How to halve a recipe
Halving is simple arithmetic until you hit ⅓ cup, three eggs or a 9 × 13 pan. Here is the order to work in.
- 1
Halve every amount
Paste the ingredient list into the scaler above and set it to half, or divide each line yourself. Work from the written recipe, not memory, so nothing gets skipped.
- 2
Turn awkward fractions into spoons
Half of ⅓ cup is 2 tbsp + 2 tsp. Half of ¾ cup is ¼ cup + 2 tbsp. Half of 1 tablespoon is 1½ teaspoons. The scaler shows these for you under each line.
- 3
Split odd eggs by weight
For half of 3 eggs, beat all three, then weigh out half. A large egg is about 50 g, so you want about 75 g. Keep the rest for scrambled eggs or an egg wash.
- 4
Use a pan with half the area
A 9 × 13-inch pan has 117 square inches; half of that is about 59, and an 8-inch square (64) is the closest common pan. The batter ends up about the same depth, so the baking time stays close.
- 5
Check for doneness early
Small differences in depth and a smaller mass of food change the timing a little. Start checking several minutes before the original time and go by the recipe's cues: a clean toothpick, golden edges, an internal temperature.
How to double a recipe
Multiply every ingredient by two, then plan the cooking rather than just the shopping. Doubled batters go into two pans of the original size, or one with twice the area: a half sheet pan (234 square inches) holds exactly two 9 × 13 recipes. Doubling an 8-inch square (64 square inches) into a 9 × 13 (117) is close, but the batter sits a little deeper, so expect a few extra minutes.
On the stove, brown meat and vegetables in batches. A doubled pile in the same pan steams instead of searing. And make sure the bowl, pot and mixer can take it: a stand mixer filled to the brim doesn't cream butter or knead dough properly.
What doesn't scale in a straight line
- Pan size. Scale by area, not by the number on the label. A 9-inch round (64 square inches) holds about what an 8-inch square (64) does, but an 8-inch round is only 50.
- Baking time. Time follows the depth of what's in the pan, not the amount. A batch of cookies takes the same time per tray however many trays you bake; a cake twice as deep takes much longer.
- Reducing liquids. Evaporation depends on the surface of the pan. A doubled sauce in the same pan takes longer to reduce; a halved one in a big pan reduces fast and can catch.
- Salt, spice and heat. Scale them, but when doubling or more, hold back a little and add the rest after tasting. It's easy to add salt and impossible to take it out.
- Roasts. Two chickens side by side roast in about the time one does; one chicken twice the size takes longer. Use a thermometer rather than the clock.
Pan sizes compared
To move a recipe to a different pan, multiply the amounts by the new pan's area divided by the old one's.
| Pan | Square inches | Square centimeters |
|---|---|---|
| 8-inch round | 50 | 324 |
| 9-inch round | 64 | 410 |
| 10-inch round | 79 | 507 |
| 8-inch square | 64 | 413 |
| 9-inch square | 81 | 523 |
| 9 × 13-inch | 117 | 755 |
| Half sheet (13 × 18-inch) | 234 | 1,510 |
Scaling and converting at the same time
The scaler keeps your units. If you also need to switch a recipe between cups and grams, scale it first, then convert with the kitchen conversion charts: grams to cups for flour, sugar and butter, tablespoons in a cup for small amounts, and oven temperatures for the oven.
Questions
How do I halve a recipe that uses 3 eggs?
Beat the 3 eggs together and use half by weight, about 75 g for large eggs. Rounding down to 1 egg leaves the batter drier; rounding up to 2 makes it wetter.
What is half of ⅓ cup?
⅙ cup, which you measure as 2 tbsp + 2 tsp.
What is half of ¾ cup?
⅜ cup, which is ¼ cup + 2 tbsp (or 6 tablespoons).
Can you double any baking recipe?
Most cakes, cookies, muffins and quick breads double well if you use two pans or a pan with twice the area, and mix in a bowl big enough to do it properly. Doubling into one deeper pan is where things go wrong: the middle needs much longer than the edges.
Does the scaler convert units too?
No, it keeps your units and only changes the amounts. Grams and milliliters stay as decimals; cups and spoons become fractions you can measure. To switch between cups and grams, use the kitchen conversion charts.
Is my ingredient list sent anywhere?
No. The scaler runs entirely in your browser; nothing you paste leaves the page.
