Homemade Shake Calculator
A homemade mass gainer shake can deliver the same calorie density as commercial powders — often with better ingredients and lower cost per serving. Enter your ingredient amounts in the calculator above and get an instant breakdown of total calories, protein, carbs and fat. This lets you adjust each shake to hit your daily surplus target without guessing.
🧮 Homemade Shake Calculator
Why Make Your Own Mass Gainer?
Commercial mass gainers often pack large amounts of sugar per serving and fill the rest with maltodextrin. When you build your own shake from whole foods, you control the carb sources, protein quality, and total calorie count. A typical homemade recipe using oats, milk, peanut butter, a banana and a scoop of protein powder can reach 800–1,200 kcal in a single glass — comparable to most off-the-shelf products.
The real advantage is flexibility. If you need more protein, add another scoop or swap in Greek yoghurt. If you want a lighter shake on rest days, cut the oats in half. The calculator on this page does the maths for you: enter each ingredient’s weight and it returns the full macro split so you can see exactly where your calories come from. That transparency makes it easier to stay within a gradual surplus of +300–500 kcal per day rather than overshooting.
Core Ingredients and What They Add
Most high-calorie shakes share a handful of base ingredients. Rolled oats are the calorie workhorse — roughly 389 kcal per 100 g of dry weight — and they blend smoothly when ground first. Whole milk adds both calories and protein: about 61 kcal per 100 g with around 3.3 g of protein. Peanut butter is the densest common add-in at approximately 588 kcal per 100 g, mostly from healthy fats.
A medium banana (about 100 g of edible flesh) contributes roughly 89 kcal plus fast-digesting carbs that improve texture. Protein powder — whey, casein or plant-based — slots in for an extra 20–30 g of protein per scoop without much volume. Optional extras include honey, cocoa powder, chia seeds or frozen berries.
The key is measuring. Eyeballing peanut butter can swing a shake by 200 kcal in either direction. Weigh each ingredient and you will get a number you can actually track against your calorie surplus target.
How to Use the Homemade Shake Calculator
Enter the weight (in grams or common measures) for each ingredient you plan to use. The calculator multiplies each entry by its nutrient density and sums the totals, giving you a per-shake breakdown of kilocalories, protein, carbohydrates and fat.
Start with a base: 80–100 g of oats, 300–400 ml of milk and a tablespoon of peanut butter. That alone puts you in the 500–700 kcal range. From there, layer in extras until you reach the surplus your body needs. If you are not sure what that surplus should be, the weight gain calorie calculator can set a daily target based on your age, height, weight and activity level.
Once you have a shake you like, save the recipe and repeat it daily. Consistency in your surplus — not variety — is what drives gradual weight gain over weeks and months. If your weight plateaus for two weeks, add 100 kcal to the shake and reassess.
Fitting the Shake into Your Surplus
Your ideal shake size depends on how much of your surplus you want in liquid form. Some people prefer one large 1,000+ kcal shake alongside normal meals. Others split it into two 500 kcal shakes — one post-workout and one before bed — to avoid the heavy, bloated feeling a single large shake can cause.
A practical guideline: your shake should cover roughly 30–50 percent of your total daily surplus. If you are aiming for a +500 kcal surplus and your meals already provide +200 kcal above maintenance, a shake in the 300 kcal range fills the gap neatly. For a broader view of ingredient costs, a grocery budget calculator can show how shake ingredients compare to whole-food meals on cost per calorie.
If you are underweight (BMI below 18.5) or have a medical condition that affects digestion, talk to your doctor before adding large calorie-dense shakes to your diet. For everyone else, start moderate and increase gradually.
Frequently asked questions
Is a homemade mass gainer as effective as a commercial one?
In terms of calories and macros, yes — a well-built homemade shake can match or exceed commercial mass gainers. The difference is ingredient quality: you choose whole-food sources like oats and peanut butter instead of maltodextrin and added sugars.
How many calories should my homemade shake have?
That depends on your total daily surplus target. Most people aiming for gradual weight gain need a +300–500 kcal surplus. If your meals cover part of that, your shake only needs to fill the remaining gap.
Can I make a homemade mass gainer without milk?
Yes. Substitute milk with oat milk, soy milk or water and compensate for the lost calories by adding more oats, nut butter or an extra scoop of protein powder. The calculator adjusts the totals automatically.
How long does a homemade shake last in the fridge?
Most shakes stay fresh for 12–24 hours when refrigerated in a sealed container. Banana-based shakes may brown but are still safe to drink. For best texture, consume within a few hours of blending.