How much do 100g dry red lentils weigh when cooked?

December 1, 2025 •

5 min read

According to cooking experts, 100g of dry red lentils can expand to weigh approximately 250 to 300 grams after being cooked. This significant weight increase is a key factor to consider for accurate meal planning and nutritional tracking, especially for those who need precise measurements.

Quick Summary

This guide explains the weight gain of dry red lentils after cooking due to water absorption. It provides the typical cooked weight for 100g of dry lentils, explores the variables that influence the final mass, and offers a comprehensive comparison with other lentil types.

Key Points

Significant Weight Increase: 100g of dry red lentils typically weigh between 250g and 300g when cooked, an increase of 2.5 to 3 times the original weight due to water absorption.
Water Absorption is Key: The weight gain comes from the lentils absorbing water, which adds mass and volume but does not increase the calorie count.
Faster Cooking and Breakdown: Split red lentils cook faster than other varieties because the husk is removed, causing them to break down easily and become mushy.
Texture Depends on Technique: For a firmer texture, use less water and drain excess liquid, while a higher water ratio and longer cooking time will result in a puree-like consistency.
Season After Cooking: To prevent lentils from becoming tough, add salt and other seasonings after the cooking process is complete.
Versatile Culinary Uses: Cooked red lentils are perfect for thick, creamy dishes like Indian dal, curries, and vegan bolognese due to their tendency to break down.
Cooked Nutrition is More Digestible: While the calorie and protein content per gram is diluted by the absorbed water, cooking increases the bioavailability of nutrients, making them easier to digest.

The Science Behind Lentil Weight Gain

The dramatic increase in weight from dry to cooked lentils is a result of a simple scientific process: rehydration. When submerged in liquid and heated, the dried lentils absorb water, causing them to swell and become softer. For split red lentils, this process happens particularly fast since the outer husk has been removed, allowing them to absorb water more quickly than their whole counterparts.

The typical ratio for red lentils is that they will expand to approximately 2.5 to 3 times their dry weight. This means that if you start with 100g of dry lentils, you can expect the final cooked weight to be somewhere in the range of 250g to 300g, depending on factors like cooking time and the amount of liquid used. This water absorption adds mass and volume but does not add calories, which is an important consideration for nutritional tracking. The original nutritional content, including protein and fiber, remains intact within the expanded lentil, simply distributed over a larger weight.

Factors Influencing the Final Weight

Several variables can affect the final cooked weight of your lentils, leading to slight variations in the 2.5x to 3x expansion ratio. Understanding these can help you achieve more consistent results.

Type of lentil

Split vs. Whole: Split red lentils, which have had their skins removed, cook faster and tend to break down into a mushy, puree-like consistency. Whole red lentils still have their outer husk and will retain their shape more, which may slightly alter the water absorption profile. Most supermarket red lentils are of the split variety.

Cooking method and duration

Stovetop Cooking: Simmering for longer periods or using more liquid can result in higher water absorption and a softer, mushier texture. For a firmer lentil, cook for a shorter time and use a lower liquid-to-lentil ratio, then drain the excess water.
Pressure Cooking: Methods like using an Instant Pot result in very soft, creamy, or mushy lentils, which are guaranteed to have absorbed a significant amount of water.

Liquid-to-lentil ratio

A higher ratio of water to lentils will naturally lead to more water absorption, especially with red lentils that are prone to breaking down and incorporating the liquid into a thicker mass. Many recipes suggest a 1:3 ratio of lentils to water for a puree-like texture.

Comparing Lentil Varieties: Dry vs. Cooked Weight

To better illustrate the difference in how various lentils absorb water, here is a comparison table showing typical expansion ratios and final weights for 100g of dry lentils.


Lentil Type	Dry Weight (g)	Approximate Cooked Weight (g)	Typical Expansion Ratio	Cooking Characteristics
Red (Split)	100g	250–300g	~2.5 to 3x	Cooks quickly (5-10 min), breaks down easily, becomes mushy. Ideal for curries, soups, and dips.
Brown	100g	200–250g	~2 to 2.5x	Holds shape fairly well, earthy flavor. Often used for soups, stews, and side dishes.
Green	100g	200–250g	~2 to 2.5x	Retains shape best, peppery flavor. Excellent for salads and other dishes where structure is desired.
Puy	100g	200–250g	~2 to 2.5x	Considered a premium lentil, holds shape exceptionally well, distinct flavor. Good for salads.

Cooking 100g Dry Red Lentils

For a perfect pot of cooked red lentils, follow these straightforward steps:

Rinse: Place 100g of dry red lentils in a fine-mesh sieve and rinse thoroughly under cool running water to remove any dust or debris.
Combine: Add the rinsed lentils to a saucepan with approximately 300ml of liquid (water or broth). This aligns with the common 1:3 ratio for a softer, puree-like consistency, ideal for red lentils.
Simmer: Bring the mixture to a boil, then immediately reduce the heat to a low simmer. Cover and cook for about 5 to 8 minutes, or until the lentils are soft and have broken down.
Drain: If your recipe requires a drier result, drain any excess liquid using the sieve. For soups or dals, the liquid is incorporated directly.
Season: For best results, season your lentils with salt and other spices after cooking, as adding salt too early can make them tough.

Conclusion

To determine how much do 100g dry red lentils weigh when cooked, the simple rule of thumb is to expect a significant weight gain due to water absorption. The final cooked mass will typically be between 250g and 300g, or roughly 2.5 to 3 times the original dry weight. This knowledge is invaluable for chefs and home cooks alike, ensuring consistency in recipes and accuracy when tracking nutritional intake. By understanding how cooking time and liquid ratios influence the outcome, you can master the art of cooking red lentils, producing perfectly cooked legumes for a variety of delicious dishes, from soups and curries to stews and dips.

Versatile Uses for Cooked Red Lentils

The soft, mushy texture of cooked red lentils makes them ideal for a range of applications beyond traditional soups and curries.

Easy Recipes

Indian Dal: A staple dish where red lentils are cooked until soft with aromatic spices like turmeric, cumin, and ginger to create a creamy, comforting meal.
Vegan Bolognese: The mushy texture of cooked red lentils makes them a perfect meat substitute for a hearty and protein-packed pasta sauce.
Red Lentil Hummus: Blending cooked red lentils with traditional hummus ingredients like tahini, lemon juice, and garlic creates a nutrient-rich and delicious dip.
Thickening Agent: Add cooked red lentils to stews or sauces as a natural thickening agent that also boosts the protein and fiber content.

Nutritional Impact of Cooking

It is also worth noting that while the protein per gram is diluted by the added water, the total amount of protein and other nutrients from the original 100g remains consistent. Cooking also increases the bioavailability of certain nutrients, making them easier for the body to absorb. This makes cooked lentils a highly nutritious and digestible food source.

One More Tip

For those who like to prep ahead, cooked lentils store exceptionally well. You can refrigerate them for 5 to 7 days or freeze for up to 6 months. This allows for quick additions to meals throughout the week.

Get the most out of your lentils

Whether you’re aiming for a specific texture for a recipe or simply curious about the cooking process, understanding how red lentils absorb liquid is the key. Embrace this knowledge to create perfect, flavorful, and nutritious dishes every time. For further information on the vast world of lentils, including different varieties and growing methods, you can visit the comprehensive database provided by the CooksInfo Food Encyclopaedia.

Frequently Asked Questions

For 100g of dry red lentils, use approximately 300ml of liquid (water or broth) for a creamy, puree-like consistency. For a firmer result, you can start with less and add as needed.

Lentils weigh more when cooked because they absorb a significant amount of water during the cooking process. This process, called rehydration, causes the lentils to swell, increasing their mass and volume.

No, cooking lentils in water does not add calories. The increase in weight comes from the absorbed water, which is calorie-free. The total calorie count for the batch of lentils remains the same as its dry state, just spread across a heavier mass.

Red lentils cook faster and tend to break down, incorporating more liquid into their texture, especially when split. Other lentils like brown or green tend to retain their shape better and may absorb slightly less liquid.

For a firmer texture, use a lower liquid-to-lentil ratio, monitor the cooking closely, and cook for a shorter time. You can also drain excess water once they reach your desired consistency.

It is best to add salt and acidic ingredients like vinegar or tomatoes after the lentils have cooked. Adding them too early can prevent the lentils from softening and make them tough.

Rinse the lentils, combine with about 300ml of water or broth, bring to a boil, then simmer for 5-8 minutes until soft. Season afterward to prevent toughening.

No, red lentils are best for recipes where a softer, mushier texture is desired, such as soups, curries, and dips. For dishes requiring firm, intact lentils (like salads), opt for brown or green lentils instead.