The short answer: multiply every ingredient in your brownies recipe by 0.5, then fix the three exceptions — leavening (about 0.75×), salt (to taste), and baking time (check early). The full scaled table below uses a standard brownies recipe that makes 16 squares and serves 8. It bakes for 25–30 minutes at 350°F (175°C). Scaled, it serves about 4 and makes about 8 squares.
All amounts in this guide are approximate, and the recipe below is an example — a standard home recipe for brownies — so you can see the scaling worked out in numbers. Your own recipe's amounts will differ; apply the factor 0.5× to whatever your recipe calls for, and use the leavening, salt and time rules on this page for the exceptions. Weigh flour and sugar when it matters: the gram figures use 120 g per cup of flour spooned and levelled (King Arthur Baking) and 200 g per cup of granulated sugar, and a cup of butter is 227 g. Where no gram figure is given, no reliable density was available in the site's ingredient data, so the amount is given by volume only — do not guess a weight for it.
The scaled recipe, in a table
| Ingredient | Original (serves 8) | Scaled ×0.5 (serves about 4) | Note |
|---|---|---|---|
| Butter | 1 cup (227 g) | 1/2 cup (114 g) | |
| Granulated sugar | 2 cups (400 g) | 1 cup (200 g) | |
| Cocoa powder | 3/4 cup | 3/8 cup | |
| Eggs | 4 | 2 | |
| All-purpose flour | 1 cup (120 g) | 1/2 cup (60 g) | |
| Salt | 1 tsp | 1/2 tsp | to taste — add most of it, then adjust |
| Vanilla extract | 2 tsp | 1 tsp | |
| Baking powder | 1/2 tsp | 3/8 tsp | scales less than the recipe — about 0.75×, a rule of thumb |
Read the table from left to right: the middle column is the recipe as written, the next column is the same recipe multiplied by 0.5×, and the note column flags the ingredients that break the rule. The baking powder uses about 0.75× (not 0.5×). Salt is listed at the scaled amount, but treat it as a starting point and taste — saltiness depends on the salt you use and the other ingredients, so a flat multiplier is a guess, not a fact. If an egg amount comes out as a half egg, crack an egg into a small bowl, beat it lightly, and use half; the rest keeps for scrambled eggs in the morning.
What does not scale
Leavening
When halving, use about 0.75× the baking powder, not 0.5×. Too much leavening makes the bake rise fast and then collapse, leaving a sunken middle and a soapy taste. This is the guidance the recipe scaler gives, and it is the single most common scaling mistake. The figure in the table is a rule of thumb, not a sourced measurement — the right amount depends on your recipe, so treat it as a starting point and adjust by feel next time.
Salt
Salt scales by feel, not by maths. Multiply it by 0.5× as a starting point, then taste — a scaled recipe with scaled salt can taste flat and salty, and a scaled-down recipe with scaled-down salt can taste dull. Fine table salt is saltier by volume than kosher salt, so if you switch salts, adjust again. The batter is the place to fix this: once the bake is in the oven, the salt is set.
Baking time
Brownies bake for 25–30 minutes, and the time changes with the depth of the batter, not with the amount of it. Two pans bake in the same time as one, because each pan holds the same depth of batter. A single deeper pan — the mistake people make when doubling into one pan — needs longer, and the edges overbake while the middle stays raw. Start checking 5–10 minutes before the recipe time: a skewer should come out with moist crumbs, not wet batter and not clean — clean means overbaked. The baking time adjuster works out an adjusted time from the pan change, and the rule is always the same — start checking 5–10 minutes before the recipe time and use a skewer.
The pan
Brownies bake in a 9x13-inch pan for a full recipe, and the pan is the scaling decision: a doubled recipe needs two 9x13-inch pans, or one 9x13-inch pan plus an 8x8-inch pan for the extra batter — never one overfilled pan. A tripled recipe needs three pans. A halved recipe fits an 8x8-inch pan, which is the classic brownie pan. Line the pan with baking paper with overhanging edges, so the slab lifts out cleanly for cutting.
Worked examples
Brownies for a party tray
A party tray needs 48 brownies, and a tripled recipe in three pans is the way to get there without a second baking session. Scale by 0.5×, bake the pans two at a time if your oven is small, and cool the slabs completely before cutting — warm brownies crumble, and a party tray of crumbs is a tragedy. Cut each slab into 16 squares, and pack them in a single layer so the tops stay shiny.
A pan sized to the evening
A brownie recipe scaled to the evening makes about 8 squares — enough for tonight and a lunchbox tomorrow, without a tray of brownies going stale by Thursday. On the smaller scalings the eggs halve cleanly, and the baking powder is adjusted by the rule in the table, not the straight multiplied amount. Check from 20 minutes on a smaller pan, because a smaller pan bakes a little faster.
Freezing brownies for later
Brownies freeze better than almost any other bake, so a doubled batch is never a waste. Cool the slab, cut it into squares, and freeze them in a single layer before bagging them, so they do not stick together. Defrost at room temperature for an hour, or warm a square in the microwave for 15 seconds and serve it with ice cream — a frozen brownie is the fastest dessert in the house.
Practical guidance
Melt the butter and stir in the sugar and cocoa while the butter is still warm, which dissolves the sugar and gives the shiny, crackly top. Add the eggs one at a time, beating briefly after each, and fold the flour in last, mixing only until it disappears. Do not overmix after the flour goes in, or the brownies turn cakey. Cool the slab completely in the pan before cutting, and use a hot, dry knife wiped clean between cuts for neat squares. For converting the scaled butter and sugar back to grams, use the cups to grams converter, and for the butter specifically see cups to grams for butter.
The classic failure when scaling brownies is a dry, cakey brownie instead of a fudgy one. Overbaking is the main cause, and scaling makes it worse because a bigger batch tempts you to leave it in longer, just to be sure. Too much baking powder is the second cause: it lifts the brownie into cake territory. Use the adjusted leavening amount in the table, check early, and remember that brownies firm up as they cool — take them out when they still look slightly underdone in the centre.
Frequently asked questions
Can I halve a brownies recipe by 0.5×?
Yes — multiply every ingredient by 0.5×, except the leavening (about 0.75×), the salt (to taste), and the baking time (check early). The table on this page works out a standard recipe serving 8 to about 4 servings. Use the recipe scaler to scale your own recipe's exact amounts.
How much baking powder do I use when I halve a brownies recipe?
Use about 0.75× the baking powder, not 0.5× — too much makes the bake rise fast and then collapse. This is a rule of thumb, not a sourced figure, so treat the table amount as a starting point and adjust by feel next time.
Does the baking time change when I halve a recipe?
Yes, but not in proportion to the recipe. The bake gets longer when the pan is fuller, but not twice as long — start checking 5–10 minutes before the recipe time and trust the skewer, not the clock. Always start checking 5–10 minutes before the recipe time — the skewer is the truth, the timer is a guess.
Do I need a different pan?
Brownies bake in a 9x13-inch pan for a full recipe, and the pan is the scaling decision: a doubled recipe needs two 9x13-inch pans, or one 9x13-inch pan plus an 8x8-inch pan for the extra batter — never one overfilled pan. A tripled recipe needs three pans. A halved recipe fits an 8x8-inch pan, which is the classic brownie pan. Line the pan with baking paper with overhanging edges, so the slab lifts out cleanly for cutting. Check the pan size converter to compare volumes before you pour; a scaled recipe needs roughly the scaled pan volume.
How do I know when brownies are done?
A skewer in the centre should come out with moist crumbs attached, not wet batter and not clean. The edges will look set and the centre will still look slightly soft — brownies firm up as they cool, so take them out a little earlier than you think.
Why did my brownies turn out cakey instead of fudgy?
Too much baking powder, too much flour, or too long in the oven. Use the adjusted leavening amount, measure the flour by weight or by spooning and levelling, and check 5–10 minutes before the recipe time.