Price-per-unit calculator
Last updated July 8, 2026
Divide the price by the package size to get the cost per ounce (or per count) — that single number makes any two packages comparable, no matter how different the sizes look. Enter two packages below and we'll do the division and unit conversion for you.
Package A
Package B
Why price per unit beats the shelf price
The bigger package is usually — but not always — the better deal. Stores count on you comparing shelf prices, not unit prices: a “family size” box at $6.49 can cost more per ounce than two regular boxes on sale. The unit price is the one number that can't be dressed up.
It's also how you catch shrinkflation
When a package quietly shrinks from 16 oz to 14.5 oz at the same price, the shelf tag doesn't change — but the price per ounce jumps 10%. Tracking cost per unit over time is the reliable way to see it; our guide on spotting shrinkflation on your receipt walks through the method.
Tips for fair comparisons
- Compare like with like: weight to weight (oz, lb, g), volume to volume (fl oz, ml, L), count to count.
- For diluted or concentrated products (juice, detergent), compare the usable amount, not the container size.
- Unit prices on shelf tags are often per different units at the same store (per oz here, per lb there) — this calculator normalizes them.
In Westchester County, NY?
Pantry Deals does this from your receipts — automatically.
Snap a receipt and every line joins your price history — then we show where your basket is cheaper across the stores you already shop. No points, no coupons, no data entry.