What this calculator does
Pasta roughly doubles in weight as it cooks, taking up water as the starch gelatinises. A factor of about 2.25 is typical, so 100 g dry becomes around 225 g cooked.
The factor matters because nutrition information and recipes disagree about which weight they mean. A serving listed as 100 g dry and one listed as 100 g cooked differ by more than a factor of two in what you actually eat, and the label rarely says which it intends.
The formula
The dry weight is multiplied by the expansion factor to give the cooked weight. The factor varies with shape and how long the pasta is cooked: around 2.0 for firmly al dente, 2.25 as a typical figure, and up to 2.5 for softer cooking or for shapes that trap more water.
| Term | Meaning |
|---|---|
| Expansion factor | Cooked weight divided by dry weight, typically 2.0 to 2.5. |
| Al dente | Cooked until still firm to the bite, which absorbs less water and gives a lower factor. |
| Dry weight | The weight as it comes from the packet, which is what most nutrition panels refer to. |
The inputs explained
| Field | What to enter |
|---|---|
| Dry pasta (g) | Dry pasta weight in grams. |
| Expansion factor | The expansion factor. 2.25 is a reasonable default; use 2.0 for firmly al dente and up to 2.5 for softer cooking. |
When to use it
Portioning by cooked weight
Recipes and meal plans often specify cooked pasta while the packet is weighed dry, and the conversion bridges the two.
Tracking nutrition accurately
Nutrition panels almost always give dry weight. Weighing cooked pasta against a dry-weight panel overstates the portion by more than double.
Cooking the right amount
Working backwards from a target cooked weight gives the dry weight to measure out, which avoids the usual outcome of cooking far too much.
Worked examples
Every figure in the tables below is produced by this page’s own calculator at build time, so the numbers and the tool always agree. Select any row to load that scenario.
What does each dry weight come to cooked?
A range of dry pasta weights converted to cooked weight.
| Dry weight | Cooked pasta weight | Cooked pasta (oz) |
|---|---|---|
| 50 g | 113 g | 4.0 oz |
| 100 g | 225 g | 7.9 oz |
| 150 g | 338 g | 11.9 oz |
| 200 g | 450 g | 15.9 oz |
Questions
How much does pasta expand when cooked?
Roughly 2 to 2.5 times its dry weight, with about 2.25 a reasonable default. Al dente pasta sits at the lower end because it has absorbed less water, and shapes with cavities that trap water sit higher.
Do nutrition labels use dry or cooked weight?
Almost always dry, since that is how the product is sold. This matters a great deal: weighing 100 g of cooked pasta and reading the panel for 100 g dry roughly doubles the calories you think you are eating relative to what you actually are.
How much dry pasta is a serving?
Commonly 75 to 100 g dry per person for a main course, which comes to around 170 to 225 g cooked. Packet guidance is often lower at around 75 g, and what people actually serve is usually higher.
Does fresh pasta expand the same way?
No, far less. Fresh pasta already contains water, so it gains much less in cooking, typically around 1.3 times rather than 2.25. The factor here is for dried pasta, and applying it to fresh will badly overestimate the cooked weight.
For rice rather than pasta, see the rice to water ratio calculator. For converting cup measures to grams, see the cups to grams calculator.