This pasta calculator tells you how much dry pasta to cook for your crowd — as a main or starter — plus the cooked yield and the water and salt to boil it in, by the Italian 1-10-100 rule.
Cooked yield ≈ 2.2× dry weight for dried durum pasta (fresh pasta gains less, ~1.4×). The 1-10-100 rule — 1 litre water, 10 g salt, 100 g pasta — keeps the boil rolling and seasons from within. Reserve a mug of the starchy water before draining: it’s the sauce emulsifier restaurants guard like currency.
100 g per Main, 1-10-100 in the Pot
Portion conventions differ by cuisine: an Italian primo runs 60–80 g dry, an American main 100 g (the box’s “56 g serving” is a label fiction few dinners obey). Grain-side counterpart: our Rice Calculator. Part of our Food Calculators collection.
Worked Example (Verified)
- 4 people, main course (defaults): 400 g dry → ≈ 880 g cooked, boiled in 4 L water with 40 g salt — one standard 500 g box minus a handful, plus leftovers insurance if the crowd upgrades its hunger setting
- Box math reality: 500 g box ÷ 100 g = 5 mains; ÷ 60 g = 8.3 starters — the pack size was designed around these numbers
- Kids scale: roughly half portions under ~8 years (50 g dry) — the calculator’s people count assumes adults; count two children as one adult
- Sauce pairing heuristic: ~100–120 mL sauce per 100 g dry pasta for dressed-not-drowned; baked pasta (lasagne sheets) portions by pan, not by this page’s boil logic
Pasta Craft Notes
- Salt the water, never the oil myth: oil in the pot does nothing but slick the strainer; salt seasons the pasta itself.
- Stir the first 30 seconds — starch release is front-loaded and clumping is decided early.
- Package times are a draft: taste 2 minutes early for al dente; finish in the sauce with pasta water for the last minute.
- Shapes matter: ridged/short shapes carry chunky sauces; long strands pair with smooth ones — portion weights stay identical.
Related Tools
- Rice Calculator — water ratios & servings for rice
- Meat Per Person Calculator — the protein course portions
- Food Calculators — the full collection
Frequently Asked Questions
How much dry pasta per person?
About 100 g dried pasta per person as a main course, 60 g as a starter/primo, 80 g as a side. That’s ~2.2× cooked weight per portion — 220 g of cooked pasta for a main. This calculator multiplies by headcount and course, then sizes water and salt by the 1-10-100 rule.
How much does pasta expand when cooked?
Dried durum pasta absorbs water to roughly 2.2× its dry weight (shape-dependent: 2.0–2.5×). 400 g dry yields ~880 g cooked. Fresh egg pasta gains less (~1.4×) and cooks in 2–4 minutes — portion fresh pasta at ~130 g per main instead.
How much water and salt for pasta?
The Italian rule 1-10-100: 1 litre of water and 10 g of salt per 100 g of pasta. Generous water keeps temperature up and starch dilute (less sticking); the salt is the pasta’s only internal seasoning. Oil in the water is a myth — reserve pasta water for the sauce instead.
Why does the box say a serving is 56 g?
US label regulation: 56 g (2 oz) is the FDA reference amount for dry pasta, inherited from older dietary frameworks. Real-world mains run 85–115 g dry. Cook for the table you have (this calculator’s settings), not the label’s reference person.
How do I measure spaghetti without a scale?
The classic guide: a bundle the diameter of a US quarter ≈ 100 g ≈ one main portion (the hole in a pasta spoon approximates it too). Weigh once, learn your handful, then eyeball forever — but the scale settles arguments the quarter can’t.
Is this pasta calculator free?
Yes — free, instant, no sign-up.