Per Serving or Per 100g? The Nutrition Label Number That Trips Snackers Up

You flip a snack pack over, spot “110 calories” in a reassuringly small font, and feel good about your choice. Then you finish the packet and wonder why you're still peckish. The number wasn't wrong — it just wasn't the number for the whole pack. One of the most useful skills in the snack aisle is knowing which column on a Nutrition Information Panel you're actually reading: per serving or per 100g. Get that straight and the label stops being able to flatter a product past you.

The two columns, and what each is really for

In Singapore, a Nutrition Information Panel (NIP) can declare values “per 100g” (or per 100ml for drinks) and/or “per serving,” according to the Health Promotion Board. When a product lists nutrients per serving, it must also state the serving size and how many servings are in the package. Those two columns answer different questions:

  • Per serving tells you roughly what you get in one portion — as the manufacturer has defined that portion.
  • Per 100g is a fixed yardstick that lets you compare two products fairly, because it's the same base amount every time.

HealthHub, run by Singapore's Ministry of Health, puts it plainly: because serving sizes vary from product to product, the per-100g figure “offers a similar base of comparison rather than serving size, which varies.”

Why “per serving” can quietly mislead you

Here's the catch: the serving size isn't a medical recommendation. It's a number the manufacturer picks, and — as HealthHub warns — “the single serving indicated may be less than what you would typically eat.” A smaller stated serving makes the calorie, sugar and sodium numbers look smaller too.

HealthHub gives a memorable example. A packet of potato chips might show 160 calories per 30g serving — and contain ten servings. Eat the whole packet in front of a show and that's a “whopping 1,600 calories,” not 160. Nothing on the label lied. The reader just read the per-serving figure and mentally applied it to the whole bag.

So the first question to ask isn't “how many calories per serving?” It's “how many servings am I actually going to eat?” If a 100g pack calls itself four servings but you know you'll finish it, multiply everything by four before you judge it.

Use per 100g to compare like with like

When you're standing between two similar snacks, the per-100g column is your friend. Product A might advertise “only 90 calories per serving” and Product B “130 per serving” — but if A's serving is 20g and B's is 35g, you're not comparing the same thing at all. Flip both to per 100g and the honest ranking appears. The Singapore Food Agency makes the same point in its guidance on reading labels before you buy: a common base lets you weigh one product against another instead of being swayed by whichever pack chose the flattering serving size.

A 15-second supermarket routine

  1. Check the serving size and servings per package — how big is one portion, and how many are in the pack?
  2. Ask yourself honestly how much you'll eat, then scale the per-serving numbers to match.
  3. Comparing two products? Switch to the per 100g column and rank them there.
  4. Zoom in on the nutrient that matters to you — calories, sodium, saturated fat, or protein — rather than trying to track everything at once.

Why the small serving matters more than it looks

This isn't just accounting. There's good evidence that the size of the portion in front of us shapes how much we eat, often without us noticing. A research review in the American Journal of Clinical Nutrition describes a well-documented “portion size effect”: give people a bigger serving and they reliably eat more, with studies finding that roughly doubling a portion can increase how much people eat by around a third. A pack that presents itself as “two servings” but pours out as one big handful is nudging you in exactly that direction.

None of this means per-serving numbers are useless — they're handy for a genuine single portion, and they're honest when the pack really is meant to be shared. And per 100g isn't a verdict on its own either: a nutrient-dense food can look “high” per 100g yet be perfectly sensible in a small, satisfying portion. The label gives you the arithmetic; the judgement is still yours. The point is simply to know which number you're looking at before you decide.

The habit worth keeping

Reading labels well isn't about fear or maths anxiety at the shelf. It's one small move — checking the serving size and, when comparing, flipping to per 100g — that stops a pack from setting the terms for you. Do it a few times and it becomes automatic.

At HexaCrunch, we'd rather you read our packs closely than take our word for it. Our baked brown-rice crackers are portioned as snacks people actually finish in one sitting, and the protein comes from cricket flour — which is why a modest serving carries more protein than the size might suggest. Curious how the numbers stack up? The Try-All 3-Pack is an easy way to turn the panel over yourself and compare.

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