The old and new package
Old package
New package
Both packages use the same unit. If the new size is printed in a different unit, convert it first. The example is made up.
Educational tool only. It compares price per unit using the numbers you enter. It does not say a price is fair, a brand is good or bad, or that you were overcharged. Not financial advice.
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How this is calculated
Unit price is the price divided by the total amount (packs times amount per pack). The change in unit price is the new unit price divided by the old one, minus 1. The change in amount is the new total amount divided by the old one, minus 1. Weight converts to weight, volume to volume and counts to counts. Fluid ounces and ounces of weight are not the same, so the tool never converts between those. The default example, $4 for 16 oz becoming $4 for 12 oz, is made up for illustration. No prices from real brands are used or stored.
Common questions
What is shrinkflation?
Shrinkflation is when a product's size or quantity goes down while its price stays the same or rises. The package may look alike, but you get less. This tool measures it as a change in price per unit.
How do you calculate shrinkflation?
Divide the price by the quantity to get the unit price, for the old and the new package. The change in unit price is new unit price divided by old unit price, minus 1. For example, $4 for 16 oz is $0.25 an oz. $4 for 12 oz is about $0.333 an oz. That is a 33.3% rise in unit price.
Why is the unit price rise bigger than the quantity drop?
Because they are measured from different bases. A 25% cut in quantity (16 oz to 12 oz) means you get one quarter less. To buy the old 16 oz at the new unit price you pay one third more. The two percentages are not the same number.
Is shrinkflation the same as inflation?
No. Inflation is a general rise in prices. Shrinkflation is one way a price per unit can rise: the shelf price stays put and the amount shrinks. A price rise with the same amount is also a unit price rise, and this tool shows both cases.
Can I compare different units, like ounces and pounds?
Yes, within the same type. The tool converts weight to weight (oz, lb, g, kg), volume to volume (fl oz, ml, L and so on) and counts to counts. It does not convert between weight and volume, because fluid ounces and ounces of weight are different things.
Does a lower unit price always mean a better deal?
No. Quality, a different recipe, how fast you use it and whether you can store it all matter too. This tool compares price per unit only. It does not say a price is fair or unfair.
What if the product is a multipack?
Enter the number of packs and the amount in each pack. The tool multiplies them to get the total quantity, so a 12-pack of 12 oz cans counts as 144 oz.
How do I check shrinkflation on a product I buy?
Note the price and size when you buy it, or check an old receipt or photo. Enter the old and new price and size here. The result shows how much less you get and what the old amount costs at today's unit price.