Use 4 quarts of water per pound of pasta — or just enough so it swims.

4 quarts per pound is the safe bet. That’s about 4 liters for 454g. You can go down to 3 quarts if you really watch it, but don’t push it further.

The logic is simple: pasta releases starch as it cooks. More water dilutes that starch, so the noodles don’t get glued together. Less water means higher starch concentration, and the temperature drops more when you drop the pasta in, which messes up the cooking. If you use less water, you have to stir immediately and keep stirring every minute or two. That works, but most people forget and end up with a clump.

Honestly, the ratio is less important than salting the water properly. Use about a tablespoon of salt per quart. And never rinse the pasta — that’s where all the stickiness comes back anyway.

So if you have the pot, use 4 quarts. If you’re in a tiny kitchen, 3 quarts is fine as long as you babysit it.