Pasta Water Calculator

For 1 pound of spaghetti, use 6 quarts of water and 6 tablespoons of kosher salt. Enter your servings below for exact measurements.

The right water-to-pasta ratio and salt amount are the foundation of great pasta.

Calculator

Pasta Shape

Servings

Oz per Serving

Water

8 qt

7.6 liters

Kosher Salt

8 tbsp

144g

Pasta

16 oz

1.0 lbs

Cook Time

9-11 min

al dente: −1 min

The Science of Pasta Water

Rule of thumb: 4-6 quarts of water per pound of pasta, 1 tablespoon kosher salt per quart.

Using enough water is critical for three reasons: First, abundant water returns to a boil quickly after you add pasta, preventing mushiness. Second, it gives pasta room to move, reducing sticking. Third, it dilutes the starch so pasta doesn't become gummy. Professional kitchens use even more water—up to 8 quarts per pound.

Salt serves two purposes: it seasons the pasta from the inside out (pasta absorbs water during cooking), and it slightly raises the boiling point, contributing to a more vigorous boil. Unsalted pasta tastes flat regardless of how flavorful your sauce is. Italian chefs say the water should taste "come il mare" (like the sea).

Serving Size Reference

Servings	Pasta	Water	Salt	Cook Time
2	8 oz	4 qt	4 tbsp	9-11 min
4	16 oz (1 lb)	6 qt	6 tbsp	9-11 min
6	24 oz	8 qt	8 tbsp	9-11 min
8	32 oz (2 lbs)	8+ qt	8 tbsp	9-11 min

Worked Example

Cooking spaghetti for 4 people (4 oz each = 16 oz total):

Water: 16 oz × 0.5 qt/oz = 8 quarts (round up from 6 minimum)
Salt: 6 quarts × 1 tbsp = 6 tablespoons kosher salt
Bring water to rolling boil, add salt, then add pasta
Cook 9-11 minutes, stir once at 1 minute
Reserve 1 cup pasta water, then drain

For al dente, taste-test 1-2 minutes before the minimum time. The pasta should have a slight bite but no white center when you break it in half.

Pro Tips for Perfect Pasta

Never add oil to the water. It prevents sauce from sticking to the pasta. Stir in the first 2 minutes instead.
Save pasta water. The starchy water is liquid gold for emulsifying sauces. Reserve 1-2 cups before draining.
Don't rinse pasta. Rinsing removes the starch that helps sauce cling. Only rinse for cold pasta salads.
Finish in the sauce. Transfer pasta to the sauce pan 1-2 minutes early and finish cooking in the sauce for better flavor absorption.
Use table salt sparingly. If using fine table salt instead of kosher, use half the amount—table salt is denser and saltier by volume.

Frequently Asked Questions

How much water do I need to cook pasta?

The classic rule is 4-6 quarts of water per pound of pasta. This ensures the pasta has room to move freely and the water returns to a boil quickly after adding pasta. Crowded pasta sticks together and cooks unevenly.

How much salt should I add to pasta water?

About 1 tablespoon of kosher salt per quart of water. The water should taste "like the sea"—noticeably salty but not unpleasant. This is your only chance to season the pasta itself. Under-salted water produces bland pasta that no sauce can fix.

Should I add oil to pasta water?

No. Oil floats on the surface and doesn't prevent sticking. It actually prevents sauce from adhering to the pasta later. The best way to prevent sticking: use enough water, stir during the first 2 minutes, and don't drain pasta until you're ready to sauce it.

What does "al dente" mean?

Al dente (Italian for "to the tooth") means the pasta is cooked through but still has a slight firmness when bitten. It should not be crunchy or have a white center. For most shapes, al dente is 1-2 minutes less than the package directions.

Should I save pasta water?

Absolutely. Starchy pasta water is the secret to great sauces. Reserve 1-2 cups before draining. Adding a splash to your sauce helps it emulsify and cling to the pasta. It's especially crucial for oil-based and cream sauces.