Shrinkflation Calculator (Real Price Increase)
Enter the old and new pack size and price.
Your numbers
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$
Your results
Real price increase per unit
Real price increase per unit
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Old price per 100 units
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New price per 100 units
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Size change
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Equivalent price at the old size
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Shrinkflation Calculator (Real Price Increase) by TheCalcTools
How the Shrinkflation Calculator (Real Price Increase) works
Shrinkflation hides price rises by shrinking the pack. Comparing price per unit (per gram, per sheet) shows the real change: (new price ÷ new size) ÷ (old price ÷ old size) − 1.
A 10% smaller pack at the same price is an 11.1% price increase per unit.
The formula
Real increase = (p₂ ÷ s₂) ÷ (p₁ ÷ s₁) − 1
Worked example
Using the default values shown in the calculator:
| Old size (g, mL, sheets…) | 500 |
|---|---|
| Old price | $3.49 |
| New size | 450 |
| New price | $3.49 |
- 500 g for 3.49 cut to 450 g at the same price: a 11.11% real price increase.
Result:
| Real price increase per unit | 11.11% |
|---|---|
| Old price per 100 units | $0.70 |
| New price per 100 units | $0.78 |
| Size change | -10.0% |
| Equivalent price at the old size | $3.88 |
Frequently asked questions
Is shrinkflation legal?
Generally yes if the new size is labelled correctly, though some countries require stores to flag it.
Sources and further reading
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This calculator gives estimates for information only. Check important results independently before you rely on them. See our disclaimer.