How to Scale a Recipe

Updated August 2026 · Baking Resources

Multiply every ingredient by your scaling factor. For flour, sugar, fat and liquid that's the whole job, and the math is honest arithmetic. The catch is that pan size, bake time, eggs, leavening and salt don't follow that rule, and those five are where scaled recipes actually fail.

So how to scale a recipe properly is a two-step job: scale the bulk ingredients straight, then handle the five exceptions on their own terms. A doubled cake batter poured into a pan that's only 27% bigger will overflow, and a tripled cookie dough with tripled baking soda will rise beautifully and then sink in the middle.

Skip the fraction headaches with our free recipe scaler, which converts any ingredient list to any factor and gives you tablespoon amounts instead of decimals.

Updated August 2026

The five things that break when you scale

Most scaling advice stops at "multiply everything." Here's what that misses.

Get the first row right and you've done 80% of the work. Get the last two wrong and it doesn't matter how precise the first row was.

The awkward fraction problem

Half of 1/3 cup is not 0.166 cups. There's no measuring cup for that, and there never will be. The real answer is 2 tablespoons plus 2 teaspoons, which you can measure exactly.

This is the single most common place home bakers give up and eyeball it. The fix is to stop thinking in cups and start thinking in tablespoons and teaspoons, because those divide cleanly where cups don't.

Everything below runs on three numbers: 1 cup = 16 tablespoons, 1 tablespoon = 3 teaspoons, so 1 cup = 48 teaspoons. Once a cup is 48 of something, halving and thirding become simple.

Halving chart

The two rows people search for constantly are 1/3 cup and 3/4 cup, and both have clean answers. Half of 3/4 cup is 6 tablespoons, full stop.

Thirding chart

Two of these don't land clean: a third of 2/3 cup and a third of 1/3 cup. Both are cases where a scale beats a spoon, which is the next section.

Doubling and 1.5x chart

Doubling is the friendly direction. Every common fraction doubles into another common fraction, which is why doubled recipes go wrong at the pan and not at the mixing bowl.

For the full breakdown of how cups divide, see cups to tablespoons, which lists every fraction down to a single tablespoon.

Weigh it and the fractions disappear

Grams have no awkward fractions. A third of 42 g is 14 g, and your scale will show you 14 g.

This is the reason professional kitchens scale by weight and never argue about half of 1/3 cup. Here are the site-standard weights, which match every calculator here:

Convert your whole ingredient list to grams once, multiply the column by your factor, and every awkward fraction problem is gone. Our grams to cups converter goes both directions if you need to hand the scaled version to someone who only owns cups.

The payoff: scaling by weight is the difference between a tripled batch that behaves like the original and one that's mysteriously dry. Volume errors compound. Triple a cup of flour measured 20 g heavy and you're 60 g over, which is nearly half a cup of extra flour.

Eggs: the one ingredient you can't cut cleanly

Half an egg doesn't exist, and eyeballing it is worse than it sounds, because an egg is both liquid, fat, protein and leavening at once.

The fix takes ten seconds. Crack the egg, beat it until the yolk and white are uniform, and weigh out what you need. A large egg out of shell is about 50 g, split roughly 30 g white and 20 g yolk.

If you have no scale, 1 large egg beaten measures about 3 tablespoons, so half an egg is 1 1/2 tablespoons. It's less exact than weighing but far better than pouring until it looks right.

Egg size matters here too. The 50 g figure is for US large eggs, which are graded by the USDA egg grading standards at a minimum of 24 oz per dozen in shell. Extra-large runs about 56 g out of shell and medium about 44 g, so a recipe built on large eggs and made with extra-large picks up an extra 12 g of liquid per egg. Across a doubled batch that's 24 g, enough to slacken a cookie dough.

What scales linearly and what doesn't

Scales straight, every time

Flour, sugar, butter, oil, milk, water, buttermilk, cocoa, cornstarch, chocolate, nuts, oats. These are bulk ingredients. Double them, triple them, take a third. The ratios that make the recipe work are preserved.

Leavening: straight to 2x, then taper

Baking powder and baking soda scale cleanly for doubling. At 3x and above, use about 75-85% of the calculated amount.

Here's why. A bigger batch means a deeper batter, and a deeper batter traps gas more efficiently and holds it longer. The full multiple of leavening builds more lift than the structure can support, so the cake domes, cracks, and then collapses as it cools. That's the same failure covered in why did my cake sink.

Round to something you can actually measure. Being 1/8 tsp light on baking powder is invisible. Being 1/2 tsp heavy is not.

Salt: scale by weight, watch the yeast doughs

Salt scales by weight, but it's the ingredient home bakers over-scale most often, because doubling "1 1/2 tsp" with a heaping spoon lands closer to 4 tsp than 3.

Salt type matters more than the multiple. A teaspoon of table salt weighs roughly twice what a teaspoon of coarse kosher salt does, so a doubled recipe made with the wrong salt is off by a factor of four in effect. Kosher salt vs table salt has the conversion.

In yeast dough, salt slows fermentation. A doubled dough already ferments differently, because a larger mass holds its own metabolic heat and rises faster than the small version did. So scale salt straight by weight, but taper the yeast to about 1.5x when you double, and start checking the bulk rise 20 minutes early. Doubling the yeast on top of a warmer, faster dough is how you get a batch that over-proofs before you get back to it.

Spices, extracts and zest: about 75% at 2x and up

Vanilla, cinnamon, nutmeg, almond extract, citrus zest and espresso powder all concentrate as batch size grows. Double the recipe, use about 1.5x the spice, taste the raw batter where it's safe to, and add more. You can always add. You can't take cinnamon back out.

Bake time: doesn't scale at all

This one surprises people. A doubled batch of cookies takes exactly the same time per tray as a single batch, because each cookie is the same size. A doubled cake in a deeper pan takes considerably longer. Batch size is irrelevant. Depth is everything. More on this below.

Pan geometry: doubling a recipe is not doubling the pan

If you double an 8-inch round recipe, you do not want a 16-inch round pan. You'd end up with a sad quarter-inch layer.

Doubling the dimensions quadruples the area. An 8-inch round has an area of about 50 square inches. A 16-inch round has 201 square inches, four times as much. To genuinely double the capacity of an 8-inch round you need about 100 square inches, which is an 11-inch round.

The math is straightforward:

• Round pan: area = 3.14 x radius x radius. A 9-inch round is 3.14 x 4.5 x 4.5 = 64 sq in.
• Rectangular or square pan: area = length x width. A 9x13 is 117 sq in.
• Scaling factor = new pan area divided by old pan area.

Read that table once and a lot of common advice makes sense. An 8-inch square and a 9-inch round hold the same amount, which is why recipes swap them freely. A 9-inch round is only 27% bigger than an 8-inch, so a doubled recipe in a 9-inch pan will run over the rim.

Our pan converter does this arithmetic for any two pans, and 9x13 pan substitutes covers the swaps for the single most common pan in American baking.

One caution: area assumes similar pan depth. Comparing a 2-inch-deep cake pan to a 4-inch-deep one needs volume, not area. If depth differs, multiply area by depth and compare those numbers instead.

Bake time: a deeper pan needs longer at a lower temperature

Heat travels from the outside in. The center of a batter is the last place to reach doneness, so the distance from surface to center sets the time.

That gives you three cases.

Same depth, bigger footprint. Nearly the same time. Check 5 minutes early because the larger mass loads the oven and drops the air temperature briefly.

Deeper batter. Lower the oven 25°F and extend the time by 25-50%. Without the temperature drop the edges set and brown long before the center is done, and you get a raw stripe down the middle of a dark-crusted cake.

Shallower batter. Raise the oven 25°F if you want equivalent browning, and start checking at 60-70% of the original time. Shallow bakes overshoot fast.

Times are starting points, not promises. Test with a skewer in the true center, and for anything bread-shaped go by internal temperature instead, which how to tell when bread is done walks through.

Run your own numbers through the baking time calculator, and if you're also switching between Fahrenheit, Celsius and convection, the oven temperature converter handles the 25°F convection offset.

How to scale a recipe step by step

Here's the full method on a real conversion: an 8-inch round cake recipe going into a 9x13 pan.

Step 1. Find the factor. 9x13 is 117 sq in. The 8-inch round is 50 sq in. 117 divided by 50 = 2.34. Round to 2.25, because a slightly shallower cake is safer than an overflowing one and 2.25 gives friendlier numbers.

Step 2. Convert the ingredient list to grams.

Step 3. Multiply the bulk ingredients by 2.25.

Step 4. Handle the eggs. 100 g x 2.25 = 225 g, which is 4.5 eggs. Beat 5 large eggs, weigh out 225 g, and save the last 25 g for brushing something.

Step 5. Handle the leavening. 1 1/2 tsp x 2.25 = 3.4 tsp. That's above 2x, so pull it back to about 85%, which lands on 1 tablespoon (3 tsp). Clean to measure and less likely to dome and crack.

Step 6. Handle the salt. 1/2 tsp x 2.25 = 1.1 tsp. Call it 1 tsp and level it properly.

Step 7. Set the pan and the time. Batter depth is roughly the same as the original because you matched area, so start at the original 350°F and add about 20%: check at 35 minutes, expect 35-40. If the batter sits deeper than about 1.5 inches, drop to 325°F and give it 45-50.

What you avoided: a 2x batch in a 9x13 would bake thin and dry out, and a straight 2.34x with 3.5 tsp of baking powder would have risen hard and sunk in the middle. The two adjustments took thirty seconds.

Scaling down is harder than scaling up

Halving works well. Quartering often doesn't, and it's worth knowing why before you try.

• Measurement error grows. Being 5 g off on 200 g of sugar is 2.5%. Being 5 g off on 50 g is 10%.
• Pans get scarce. A quarter of a 9x13 is 29 sq in, which is roughly a 6-inch round or a mini loaf pan. Most kitchens don't have a good quarter-size option.
• Mixers stop working. A stand mixer with a quarter batch of creamed butter mostly moves air around above the paddle. Switch to a hand mixer or a bowl and spatula.
• Evaporation changes. A small batch loses a higher percentage of its moisture in the oven, so small versions bake drier at the same time and temperature.

For anything below half, halve twice with a scale rather than dividing by four in your head, and drop the bake time to about 60% of the original as a starting check.

Five mistakes that ruin a scaled recipe

1. Scaling everything, including the bake time. Time follows depth, never batch size.
2. Matching pan dimensions instead of pan area. Doubling both sides quadruples the pan.
3. Guessing at half an egg. Beat and weigh. It takes ten seconds.
4. Full leavening at 3x and up. Use 75-85% and skip the collapsed center.
5. Scaling volume measurements of flour. Errors multiply. Weigh the flour and the problem never appears, which is the whole argument in how to measure flour.

How to scale a recipe FAQ

What is half of 1/3 cup?

2 tablespoons plus 2 teaspoons. A third of a cup is 16 teaspoons, so half of it is 8 teaspoons, and 8 teaspoons is 2 tbsp + 2 tsp. By weight it's 21 g of all-purpose flour or 33 g of granulated sugar.

How do I double a recipe without it failing?

Double the flour, sugar, fat and liquid straight, ideally by weight. Double the eggs, salt and leavening too, since 2x is still in the safe range. Then fix the pan by area, not dimensions, and expect the bake time to change only if the batter sits deeper.

Can I just double the pan size when I double a recipe?

No, and this is the most expensive mistake in scaling. Doubling both dimensions gives you four times the area. To double the capacity of an 8-inch round you want about an 11-inch round, and to double a 9x13 you want two 9x13 pans.

How much does one egg weigh for scaling?

About 50 g out of shell for a US large egg, split roughly 30 g white and 20 g yolk. Beat the egg first, then weigh out the fraction you need. Extra-large runs about 56 g and medium about 44 g, which matters once you're multiplying by three or four.

Do I scale baking powder the same as everything else?

Up to 2x, yes. At 3x and above use about 75-85% of the calculated amount, because a deeper batter holds gas more efficiently. Too much leavening in a big cake produces a fast rise, a cracked dome, and a sunken center as it cools.

Should I change the oven temperature when I scale up?

Only if the batter gets deeper. Same depth means the same temperature and roughly the same time. Deeper means dropping 25°F and adding 25-50% to the time so the center cooks before the edges overbake.

How do I scale a recipe by 1.5?

Multiply everything by 1.5, which is friendlier than it looks: 2/3 cup becomes 1 cup, 1/2 cup becomes 3/4 cup, and 1/3 cup becomes 1/2 cup. For eggs, 2 eggs becomes 3 and 3 eggs becomes 150 g x 1.5 = 225 g, so beat 5 and weigh out 225 g.

Is it better to scale by weight or by volume?

Weight, without question, and the gap widens as the factor grows. Volume measuring has a built-in spread of up to 26% on flour alone, and multiplying by three multiplies that error too. Grams also divide cleanly, so a third of 42 g is simply 14 g.

Related guides: Recipe scaler | Pan converter | Baking time calculator | Oven temperature converter | Cups to tablespoons | Grams to cups | Ingredient weights | Baking conversion chart | How to measure flour | 9x13 pan substitutes