About the Protein Powder Serving Calculator
This protein powder calculator compares two products on what actually matters — the price you pay per gram of protein, not per tub or per scoop. Enter each powder’s price, container size, serving size and grams of protein per serving, and it works out servings per container, cost per serving, cost per 100 g of protein and the protein percentage by weight.
It is useful when shopping between a big tub and a smaller one, whey versus plant protein, or a cheap powder with a large scoop full of fillers versus a pricier isolate. Add how much protein you want from powder each day and it also shows how many scoops that takes, how long a container lasts and the monthly cost.
Use the serving size and protein per serving printed on the Nutrition or Supplement Facts label, and the net weight of the container. The calculator assumes the label is accurate; independently tested brands give more confidence that you are getting the protein you pay for.
With the default inputs, the powder a cost per 100 g protein is $3.13. Change any value above to recalculate instantly.
How to use the protein powder serving calculator
- 1Choose whether container sizes are in pounds or kilograms.
- 2Enter Powder A’s price, net weight, serving size and protein per serving from the label.
- 3Enter the same details for Powder B.
- 4Enter how much protein you want from powder each day.
- 5Compare the cost per 100 g of protein, scoops per day and monthly cost.
Formula and method
The container’s net weight (pounds × 453.6 or kilograms × 1,000) divided by the serving size gives the number of servings. Multiplying by grams of protein per serving gives the total protein you are buying, and dividing the price by that total gives the cost per gram — the fairest way to compare powders with different scoop sizes and protein contents.
Protein by weight is protein per scoop ÷ scoop weight; whey isolates are typically around 85–90%, concentrates about 70–80%, and blends or gainers much lower. Scoops for your target divide your daily protein from powder by the protein per scoop, and days a container lasts divide total protein by that daily amount.
- Net weight
- Container contents in grams
- Scoop
- Serving size in grams from the label
- Price
- What you pay for the container
Worked examples
5 lb tub vs 2 lb tub
The 5 lb tub holds 2,268 g, or 73.2 scoops of 31 g, providing 1,756 g of protein for $54.99 — $3.13 per 100 g. The 2 lb tub provides 687 g of protein for $34.99, or $5.09 per 100 g, so the big tub is about 38% cheaper per gram of protein.
Whey isolate vs budget blend (kg)
The isolate gives 33.3 servings × 27 g = 900 g of protein for $45, or $5.00 per 100 g. The cheaper blend gives 25 servings × 22 g = 550 g of protein for $30, which is $5.45 per 100 g — so despite the lower price and lower cost per scoop, the isolate is better value per gram of protein.
Frequently asked questions
How do I calculate the cost per gram of protein?+
Divide the container’s net weight by the serving size to get servings, multiply by grams of protein per serving to get total protein, then divide the price by total protein. Multiply by 100 for cost per 100 g, which is easier to compare.
How much protein is in one scoop of protein powder?+
Most whey and plant powders provide about 20–30 g of protein per scoop, but scoop sizes range from roughly 25 g to 45 g. Check the label: grams of protein per serving matters more than the number of scoops.
Is a bigger tub of protein powder always cheaper?+
Usually per gram of protein, but not always — sales, subscription discounts and differences in protein content can flip the result. Comparing the cost per 100 g of protein is the reliable way to tell.
What protein percentage should a good protein powder have?+
Whey isolate is typically about 85–90% protein by weight and whey concentrate about 70–80%. Powders well below 70% usually contain added carbohydrate, fats, flavouring or thickeners, so you pay for less protein per gram.
How many scoops of protein powder should I have a day?+
Powder is a convenience, not a requirement. Most people use one or two scoops a day to help reach their total protein target, with the rest coming from food. Use the protein calculator to find your daily total first.