Serving size change calculator
Bigger scoop or different amount? Put your old and new labels on the same basis.
Hypothetical labels, not real product findings. Replace them with your two labels.
Example comparison · Per gram of powder
12.5% less
Declared ingredient per equal gram of powder
- Old label / gram of powder
- 0.8 g
- New label / gram of powder
- 0.7 g
- Old → new / whole label serving
- 24 g → 28 g
- Change per whole label serving
- 16.667% more
The entered amount per unit differs. This does not confirm a formula change or establish why the label changed.
Label arithmetic for one ingredient, not a confirmed Signal, product test or suggestion to change your serving. Printed rounding and label errors can affect the comparison. Numbers stay in your browser.
How it works
Same ingredient.
Same comparison basis.
Start with two labels for the same product, flavor and market. Keep their dates. Copy the serving size and one ingredient’s amount from the same column on each label. For powder, use serving weight in grams. For capsules, use the count per label serving.
FDA’s supplement labeling guide distinguishes amounts per serving from optional amounts per unit. A serving can contain several capsules. The panel’s column heading determines which amount you are reading.
Ingredient per gram or item = ingredient amount per label serving ÷ grams or items in that serving
Normalized change (%) = (new amount per gram or item ÷ old amount per gram or item − 1) × 100
Per-serving change (%) = (new declared amount ÷ old declared amount − 1) × 100
More per scoop, less per gram
| Label numbers | Old | New |
|---|---|---|
| Powder / serving | 30 g | 40 g |
| Protein / serving | 24 g | 28 g |
| Protein / gram of powder | 0.8 g | 0.7 g |
The printed protein amount rises about 16.67% per serving. On an equal powder weight, it falls 12.5%. That is a comparison of declared figures, not proof of reformulation or a recommendation to change your serving.
One capsule becomes two on the label
If the old panel says 200 mg per one capsule and the new panel says 400 mg per two capsules, both declare 200 mg per capsule. Other ingredients or ingredient forms may still differ. An equal number for one line does not establish an unchanged formula.
Before calling it a change
Match flavor, country, product format, chemical form and preparation basis. Compare elemental mineral amounts with elemental amounts. Never substitute a proprietary blend total, percent Daily Value, IU, extract ratio or an unknown amount for a known ingredient mass.
Keep the original panels: printed rounding and corrections can affect the arithmetic. For a documented change, follow the dated sources in the Record and any confirmed Signal. Your inputs here do not become research evidence.
Method and source checked October 29, 2026. FDA labeling guide, Chapter IV (Serving Size and Amounts). FDA has not reviewed or endorsed this tool.
Questions
Scoop, capsule and label questions.
My protein scoop got bigger. Did the protein concentration change?
Divide protein grams by powder grams on each label. Compare those ratios, rather than protein per scoop alone. A hypothetical old serving of 24 g protein in 30 g powder is 80% protein by declared mass; 28 g in 40 g is 70%. Protein per serving rose, but protein per gram fell 12.5%. This is label arithmetic, not lab testing.
Can more protein per serving mean less protein per gram?
Yes. In the example, protein per serving rises from 24 g to 28 g, or about 16.67%, while powder weight rises from 30 g to 40 g, or about 33.33%. Protein per gram falls from 0.8 g to 0.7 g. A higher front-label number alone cannot answer the concentration question.
The label changed from one capsule to two. Did the ingredient amount double?
Compare per capsule. An old declaration of 200 mg per one capsule and a new declaration of 400 mg per two capsules both work out to 200 mg per capsule. The declared serving amount doubled; the per-capsule amount did not. This does not establish that other ingredients stayed the same.
Does 500 mg per serving mean 500 mg in each capsule?
Only if one capsule is the stated serving. If the panel declares 500 mg per two capsules, the arithmetic is 250 mg per capsule. Read the column heading as well as Serving Size. Do not interpret the result as advice about how many capsules to take.
Can I compare grams on one label with milligrams on the other?
Yes, for the same ingredient and chemical form on the same basis. One gram is 1,000 milligrams, and one milligram is 1,000 micrograms. Choose each label’s own mass unit. The result-unit selector only changes the display. IU, enzyme activity and percentage Daily Value are not mass units and are not accepted.
Can I compare scoop counts without knowing the grams?
Not reliably across different scoops. Scoop volume, powder density and fill can differ. For powder, enter the grams per serving printed on each label. Do not assume an old scoop holds the new label serving, or convert a tablespoon to powder grams without a matching measured weight.
Can I compare gummies, tablets and softgels?
Yes, within the same item type. Select that type, then enter the count in each whole label serving and the ingredient amount for that serving. Do not compare capsules with gummies by item count: their sizes and formulations differ. A per-item comparison is not a per-gram concentration measurement.
Is magnesium glycinate weight comparable to elemental magnesium?
No. The whole compound and its elemental magnesium are different quantities. Compare elemental with elemental, or the identical compound with the identical compound. The calculator does not infer elemental content, absorption, extract strength or biological equivalence. Leave the comparison box unchecked when the bases do not match.
Can I use a proprietary blend total for one ingredient?
No. A blend total does not disclose each component’s amount. Use the same named, quantitatively disclosed ingredient line on both labels. A missing amount, an unlisted line or a less-than value is not an exact zero and cannot be entered as one here.
What if the old amount is zero or the new amount is zero?
Use zero only when it is a known numeric declaration. When the old amount is zero there is no defined percentage-change baseline; the tool shows the two amounts without a percentage. A positive old amount changing to a declared zero is a 100% decrease in the entered figures. Printed zero can reflect label rounding, rather than proven absence.
Does a per-gram difference prove a formula change?
No. Label rounding, a correction, flavor, country, ingredient form or preparation basis can explain a difference. Match the exact product, flavor and market, keep both label dates, and check the sources. A confirmed FormulaSignal Signal requires comparable dated evidence and its own release checks. This calculator never creates a Signal.
Does this tell me whether the bottle shrank or became worse value?
No. Serving-size changes, net package size and price are separate questions. A larger serving can reduce the printed serving count without reducing the net powder weight. Check net weight and actual prices. Use the protein powder cost calculator for price per equal protein amount; this tool only compares one declared ingredient.
Does equal concentration mean the products are interchangeable?
No. Matching one ingredient amount says nothing about the rest of the formula, ingredient form, purity, absorption, safety or effectiveness. Do not use the comparison to change a serving, split capsules or substitute a supplement. Follow the label and consult a qualified professional for personal use questions.
Are my old and new label numbers uploaded or saved?
No. The comparison runs in your browser without an account. This tool does not upload or save the entered quantities. Reloading restores a clearly labeled hypothetical example. Changing the comparison basis clears both labels so powder weights cannot silently become capsule counts.