PriceXraythe price-per-unit x-ray machine

Shrinkflation Calculator

The bag got quieter, the box got lighter, the price tag played innocent. Here's the receipt.

Enter the old size and price and the new size and price. You get the real percentage increase in what you're paying per ounce/sheet/count — including the favorite trick where the shelf price "didn't change" at all.

Use the same unit for both sizes (oz vs oz, sheets vs sheets, count vs count).

Before

Old size (oz, sheets, count — your pick, just be consistent) Old price ($)

After

New size (same unit as the old size) New price ($)

Pre-filled example: same $3.49 shelf price, bottle quietly drops from 16.9 to 15.2 oz. "The price didn't go up." Sure it didn't.

Why this keeps happening

Package-price comparisons are easy to game and unit-price comparisons aren't — so the packaging changes and the shelf price doesn't. It's legal, it's everywhere, and NPR, consumer agencies, and every local news "family budget" segment through 2026 give the same one-line defense: watch the unit price.

That's not a coincidence. Unit price is the one number the package can't spin. Size drops? Unit price rises and tells on it. "Bonus 25% more!"? Unit price says whether it's actually a deal. New "family size"? Unit price is unimpressed.

Make unit price your default, automatically

PriceXray searches Amazon and sorts everything by price per unit — per oz, per sheet, per count — so shrinkflation has nowhere to hide. Add Walmart, eBay and Google Shopping to the same search with one tap.

Search anything by unit price → See this month's staple price report →

The monthly report tracks 42 everyday staples and flags month-over-month unit-price creep — when the peanut butter got 5% more expensive per ounce without the jar price moving, that's where it shows up.

FAQ

What is shrinkflation?: A price increase disguised as a packaging change: the product shrinks, the price doesn't. Per unit, you're paying more; per shelf tag, nothing happened.
How is it calculated?: Compare unit prices: (new price ÷ new size) vs (old price ÷ old size). The percent change between them is the real increase. That's exactly what the calculator above does.
How do I protect myself?: Shop by unit price. Shrinkflation only works on package-price comparisons — it's powerless against per-oz/per-sheet/per-count math.

More tools

Our Amazon links are plain links — no affiliate tag, no commission.

Amazon doesn't allow affiliate sites to run price alerts, so we chose the alerts. If eBay or Walmart links ever earn us a commission, they'll be labeled (paid link) — and it never changes the price you pay. The whole thing runs on Ko-fi tips.

This calculator runs entirely in your browser — nothing you type is sent anywhere.

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