The short answer: multiply every ingredient in your tomato soup recipe by 3, then fix the three exceptions — leavening (none in this recipe), salt (to taste), and cooking time (check early). The full scaled table below uses a standard tomato soup recipe that makes 8 cups and serves 8. It simmers for about 30 minutes on the hob. Scaled, it serves about 24 and makes about 24 cups.
All amounts in this guide are approximate, and the recipe below is an example — a standard home recipe for tomato soup — so you can see the scaling worked out in numbers. Your own recipe's amounts will differ; apply the factor 3× 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 ×3 (serves about 24) | Note |
|---|---|---|---|
| Chopped tomatoes | 8 cups | 24 cups | |
| Onions, chopped | 2 | 6 | |
| Garlic cloves | 4 cloves | 12 cloves | |
| Olive oil | 2 tbsp | 6 tbsp | |
| Vegetable stock | 4 cups | 12 cups | |
| Cream | 1/2 cup | 1 1/2 cups | |
| Granulated sugar | 1 tbsp | 3 tbsp | |
| Salt | 1 tsp | 3 tsp | to taste — add most of it, then adjust |
| Dried basil | 1 tsp | 3 tsp |
Read the table from left to right: the middle column is the recipe as written, the next column is the same recipe multiplied by 3×, and the note column flags the ingredients that break the rule. There is no leavening in this recipe, so nothing in the table breaks the leavening rule. 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
There is no leavening in tomato soup — no baking powder, no baking soda, no yeast — so this exception simply does not apply here. That is one less thing to get wrong, and it is why tomato soup is one of the most forgiving recipes to scale: every ingredient multiplies by 3×, and the only things that need judgement are the salt, the cooking time and the size of the pot or dish.
Salt
Salt scales by feel, not by maths. Multiply it by 3× 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. For soup, the salt goes in after simmering, once the flavour has concentrated; for baking, the batter is the place to fix it, because once the bake is in the oven the salt is set.
Cooking time
The simmer stays about 30 minutes whatever the batch size, because simmering is about flavour, not volume. A bigger pot takes a few extra minutes to come to the boil, so allow for that, but once it is simmering the clock is the same. Taste at the end, not at the start — the flavour concentrates as the soup reduces, and the salt should be adjusted after simmering, not before. The baking time adjuster is for oven bakes, but the principle is the same: start checking 5–10 minutes before the recipe time and trust your senses, not the clock.
The pan
Tomato soup is scaled by the pot, not the pan: a doubled recipe needs a pot at least twice as big, because soup that fills a pot to the brim boils over the moment it simmers. A tripled recipe needs a stockpot, and a halved recipe fits a medium saucepan. Leave at least two inches of headroom at the top of the pot, and remember that a bigger pot of soup takes longer to come to the boil, even though the simmering time stays about the same.
Worked examples
Soup for a crowd at lunch
A pot of tomato soup is the easiest lunch for a crowd, and a tripled recipe feeds twelve with bread and cheese on the side. Scale by 3× in a stockpot, let it come to a simmer slowly, and blend it in batches — never fill a blender more than halfway with hot soup. Serve it in mugs rather than bowls if people are standing, and put the cream on the table so everyone seasons their own.
A pot sized to the household
The scaled recipe makes about 24 cups of soup, which is lunch for one person for two days or supper for a family with grilled cheese. The only ingredient that needs care is the salt: add the scaled amount, simmer, and taste at the end, because the soup concentrates as it reduces. Freeze any extra in a tub, label it with the date, and you have a homemade lunch waiting for a busy day.
Freezing soup for the month
Tomato soup freezes better than almost any other soup, so a doubled batch is a month of lunches in one afternoon. Cool the soup completely, freeze it in portions without the cream — cream splits when frozen — and stir the cream in when you reheat it. Reheat gently, never boil it, and taste for salt again after reheating, because freezing dulls seasoning slightly.
Practical guidance
Cook the onions gently in the olive oil until soft and sweet, about 8–10 minutes, before the tomatoes go in — rushed onions stay sharp and the soup tastes raw. Add the garlic for the last minute only, because burnt garlic turns bitter and a big pot of bitter soup is hard to rescue. Blend the soup in batches, filling the blender only halfway, because hot soup expands and a full blender lid blows off. Stir the cream in at the very end, off the heat, so it does not split. For converting the scaled cream and stock measures, use the cups to grams converter for any ingredient you weigh rather than measure.
The classic failure when scaling tomato soup is a soup that is either too thin or too acidic. Too much stock makes it watery, and scaling the stock by the same factor as the tomatoes is correct — the mistake is adding extra stock later, just in case. Acidity comes from the tomatoes themselves, so taste before adding sugar: a pinch of sugar balances sharp tomatoes, but too much makes the soup taste sweet. If the soup is too thin, simmer it uncovered for 10 minutes to reduce it rather than adding more tomatoes.
Frequently asked questions
Can I triple a tomato soup recipe by 3×?
Yes — multiply every ingredient by 3×, except the leavening (there is none in this recipe), the salt (to taste), and the cooking time (check early). The table on this page works out a standard recipe serving 8 to about 24 servings. Use the recipe scaler to scale your own recipe's exact amounts.
Is there any leavening to adjust in tomato soup?
No — tomato soup contains no baking powder, baking soda or yeast, so there is no leavening to adjust. Every ingredient scales by 3×, and the only judgement calls are the salt, the cooking time and the size of the pot or dish.
Does the cooking time change when I triple a recipe?
Yes, but not in proportion to the recipe. A bigger pot takes longer to come to the boil, but the simmer stays about 30 minutes. 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?
Tomato soup is scaled by the pot, not the pan: a doubled recipe needs a pot at least twice as big, because soup that fills a pot to the brim boils over the moment it simmers. A tripled recipe needs a stockpot, and a halved recipe fits a medium saucepan. Leave at least two inches of headroom at the top of the pot, and remember that a bigger pot of soup takes longer to come to the boil, even though the simmering time stays about the same. Check the pan size converter to compare volumes before you pour; a scaled recipe needs roughly the scaled pan volume.
Should I add the cream before freezing tomato soup?
No — freeze the soup without the cream, because cream can split when frozen and reheated. Stir the cream in after reheating, off the heat, and the soup will be smooth.
How do I fix tomato soup that tastes too acidic?
Add a pinch of sugar — half a teaspoon at a time — and taste after each addition. A small knob of butter stirred in at the end also rounds off acidity. Do not add more salt to fix acidity; salt and sugar do different jobs.