How do you scale a recipe for a client's household?
In short: Divide the number of servings you need by the number the recipe makes, and multiply every ingredient by that factor. Nutrition per serving stays the same as long as the portion does, because the totals and the number of servings grow together. Seasoning, liquid that cooks off, cooking times and pan sizes don't scale in a straight line, so adjust those by eye and taste.
1 min 4 s videoCaptions onUpdated 29 September 2026
The scaling factor
Everything starts from one number. Work it out, then apply it to every ingredient, weighed in grams or millilitres where you can.
Scaling factor = servings you need ÷ servings the recipe makes Recipe serves 4, household of 6: 6 ÷ 4 = 1.5 Beef mince: 500 g × 1.5 = 750 g Tinned tomatoes: 400 g × 1.5 = 600 g
Scaling down works the same way. A recipe for four cooked by a client who lives alone has a factor of 0.25, or 0.5 if they'd like a second portion for tomorrow's lunch.
Why nutrition per serving stays the same
Scaling multiplies the whole recipe, and the number of servings goes up by the same factor. The energy in each portion doesn't move.
Original: 2400 kcal ÷ 4 servings = 600 kcal per serving Scaled ×1.5: 3600 kcal ÷ 6 servings = 600 kcal per serving
What does change is the portion when people don't eat equal shares. If two teenagers eat one and a half portions each, a family of four eats five portions, not four. Scale to five, and your client's portion is still one serving at 600 kcal.
When portions really vary, weigh the finished dish and work per 100 g. How to calculate calories and macros in a recipe shows how to use cooked weight.
What doesn't scale in a straight line
- Salt and strong spices. Chilli, cumin and salt can overpower a large batch. Add them at a little under the factor, then taste and adjust.
- Liquid that cooks off. Evaporation depends on the pan's surface, not on how much is in it. A doubled sauce in a wider pan may need less extra liquid than the maths says, and one in a deep pot may need longer to reduce.
- Cooking time. A bigger joint or a deeper tray takes longer, because heat has further to travel to the centre. Go by thickness and a thermometer rather than by the clock.
- Pan and tin size. Tray bakes scale by area, not by width. A 20 cm square tin is 400 cm². Doubling the recipe needs about 800 cm², such as a 28 cm square tin or two 20 cm tins, or the bake will be twice as deep and undercooked in the middle.
- Baking. Raising agents, eggs and setting times are less forgiving. Scale a cake by making two, or weigh beaten egg (a medium egg is roughly 50 g out of the shell) when the factor leaves you with half an egg.
A bigger batch also takes longer to cool. Split it into shallow containers before it goes in the fridge. Turning a meal plan into a meal prep plan covers storage.
Round for the shop, then check the plan
Scaled amounts rarely match what's on the shelf. 750 g of mince when packs come in 500 g means buying 1 kg or changing the servings. Round counted items to whole ones too. Nobody buys a quarter of a tin of chickpeas.
Rounding changes the numbers, so decide which way it goes. You can round the recipe up and plan the extra as a leftover, or keep the exact amounts and freeze what's left of the pack. Either works. What matters is that the portion your client eats is still the one in their plan.
How to do it in Foodzilla
Foodzilla scales recipes in a few places: in the recipe itself, when you add it to a plan, in the grocery list and in the meal plan PDF. The video shows each one.
- 1To change a saved recipe's size, open it from My Recipes and edit it. On the Details tab, change Number of servings. Foodzilla scales every ingredient amount and the recipe totals with it, so the nutrition per serving stays the same.
- 2When you add a recipe to a meal plan, choose Use One Serving to add a single portion, with the ingredients and nutrition divided to match, or Use All Servings to add the whole recipe.
- 3On the plan's Grocery List tab, open List Settings and set Serving Calculation. One Serving divides each recipe by its number of servings, and All Servings buys the full recipe as written.
- 4To print a plan for a household, press PDF in the plan and set Scale recipe quantities to between 2 and 6 people. The recipes and grocery list in the PDF are multiplied, and the plan itself stays set for your client.
- 5When you swap a meal with Auto-Swap (Professional plan and above), Smart Auto-Scale adjusts the replacement's ingredients so it keeps a similar energy and nutrient profile to the recipe it replaces.
Good to know
- Keep servings wholeFoodzilla's meal plan auto-generator leaves out recipes with fractional servings, such as 2.5. Round to a whole number of servings if the recipe should be available for auto-generated plans.
- Scale the plan, not the clientSet the plan to your client's portion and scale the shopping for the household. Their targets stay right, and the family still gets fed.