Spice Scaling Calculator

Spice scaling adjusts seasoning quantities when you change how much a recipe makes. Most ingredients scale linearly, so double the batch and you double the flour. Spices do not.
Chilli, cayenne and black pepper are never doubled outright when a recipe is doubled, because perceived heat climbs faster than the amount in the pot does.

Linear scaling formula (for most ingredients): Scaled Amount = Original Amount × (New Servings ÷ Original Servings)

Non-linear spice scaling (for everything with a real punch to it): Scaled Spice = Original Spice × (Scale Factor)^exponent

Where:

• Original Amount: the quantity in the original recipe
• New Servings: your target batch size
• Original Servings: the recipe’s intended yield
• Scale Factor: New Servings ÷ Original Servings
• Exponent: below 1 for anything strong, so the amount grows more slowly than the batch does

The exponent is a rule of thumb, not a law of nature. It comes from the same place every cook eventually arrives at after doubling a curry and finding it inedible. What it encodes is that perceived pungency rises faster than concentration, so matching the concentration overshoots the taste.

Mild herbs sit at 1.00, which is ordinary linear scaling. They are on the list precisely because they are the exception: you can double the parsley and nothing bad happens.

The rule works in both directions. Halving a recipe and halving the cayenne with it leaves the dish tasting flat, because the same curve that says “less than double when doubling” says “more than half when halving”. At an exponent of 0.60, halving the batch means keeping about 66% of the chilli, not 50%.

Worked example: Original recipe serves 4, using 1 tsp cumin, ½ tsp cayenne, 2 tsp paprika and ¾ tsp salt. Scaling to serve 12, so the scale factor is 3.

• Cumin (moderate): 1 × 3^0.85 = 1 × 2.54 = ~2½ tsp
• Cayenne (very strong): 0.5 × 3^0.60 = 0.5 × 1.93 = ~1 tsp
• Paprika (moderate): 2 × 3^0.85 = 2 × 2.54 = ~5 tsp (1¾ tbsp)
• Salt: 0.75 × 3^0.80 = 0.75 × 2.41 = ~1¾ tsp

Straight multiplication would have asked for 3 tsp of cumin, 1½ of cayenne, 6 of paprika and 2¼ of salt. The cayenne is where you would have noticed.

Always taste and adjust at the end. These are starting points, not final answers.